Ion channel modulating compounds and uses thereof

ABSTRACT

Ion channel modulating compounds are disclosed. The compounds of the present invention may be incorporated in compositions and kits. The present invention also discloses a variety of in vitro and in vivo uses for the compounds and compositions, including the treatment of arrhythmia and the production of analgesia and local anesthesia.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.11/757,880 filed Jun. 4, 2007, now allowed; which is acontinuation-in-part of U.S. patent application Ser. No. 11/619,136filed Jan. 2, 2007, now pending; which is a continuation of U.S. patentapplication Ser. No. 11/342,270 filed Jan. 27, 2006 (U.S. Pat. No.7,259,184); which is a continuation of U.S. patent application Ser. No.11/018,428 filed Dec. 21, 2004 (U.S. Pat. No. 7,057,053); which is acontinuation of U.S. patent application Ser. No. 10/674,684 filed Sep.29, 2003 (U.S. Pat. No. 7,101,877); which is a continuation of U.S.patent application Ser. No. 09/680,988, filed Oct. 6, 2000 (abandoned).These applications are incorporated herein by reference in theirentireties.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is generally directed toward ion channelmodulating compounds, pharmaceutical compositions and kits containingthe ion channel modulating compounds, and therapeutic uses thereof.

2. Description of the Related Art

Cardiac ion channels are proteins that reside in the cell membrane andcontrol the electrical activity of cardiac tissue. In response toexternal stimuli, such as changes in potential across the cell membrane,ion channels can form a pore through the cell membrane, and allowmovement of specific ions into or out of the cell. The integratedbehavior of thousands of ion channels in a single cell results in an ioncurrent, and the integrated behavior of many ion currents makes up thecharacteristic cardiac action potential.

Arrhythmia is a variation from the normal rhythm of the heart beat andgenerally represents the end product of abnormal ion-channel structure,number or function. Both atrial arrhythmias and ventricular arrhythmiasare known. The major cause of fatalities due to cardiac arrhythmias isthe subtype of ventricular arrhythmias known as ventricular fibrillation(VF). Conservative estimates indicate that, in the U.S. alone, each yearover one million Americans will have a new or recurrent coronary attack(defined as myocardial infarction or fatal coronary heart disease).About 650,000 of these will be first heart attacks and 450,000 will berecurrent attacks. About one-third of the people experiencing theseattacks will die of them. At least 250,000 people a year die of coronaryheart disease with 1 hour of the onset of symptoms and before they reacha hospital. These are sudden deaths caused by cardiac arrest, usuallyresulting from ventricular fibrillation.

Atrial fibrillation (AF) is the most common arrhythmia seen in clinicalpractice and is a cause of morbidity in many individuals (Pritchett E.L., N. Engl. J. Med. 327(14):1031 Oct. 1, 1992, discussion 1031-2;Kannel and Wolf, Am. Heart J. 123(1):264-7 Jan. 1992). Its prevalence islikely to increase as the population ages and it is estimated that 3-5%of patients over the age of 60 years have AF (Kannel W. B., Abbot R. D.,Savage D. D., McNamara P. M., N. Engl. J. Med. 306(17):1018-22, 1982;Wolf P. A., Abbot R. D., Kannel W. B. Stroke. 22(8):983-8, 1991). WhileAF is rarely fatal, it can impair cardiac function and is a major causeof stroke (Hinton R. C., Kistler J. P., Fallon J. T., Friedlich A. L.,Fisher C. M., American Journal of Cardiology 40(4):509-13, 1977; Wolf P.A., Abbot R. D., Kannel W. B., Archives of Internal Medicine147(9):1561-4, 1987; Wolf P. A., Abbot R. D., Kannel W. B. Stroke.22(8):983-8, 1991; Cabin H. S., Clubb K. S., Hall C., Perlmutter R. A.,Feinstein A. R., American Journal of Cardiology 65(16):1112-6, 1990).

Antiarrhythmic agents have been developed to prevent or alleviatecardiac arrhythmia. For example, Class I antiarrhythmic compounds havebeen used to treat supraventricular arrhythmias and ventriculararrhythmias. Treatment of ventricular arrhythmia is very important sincesuch an arrhythmia can be fatal. Serious ventricular arrhythmias(ventricular tachycardia and ventricular fibrillation) occur most oftenin the presence of myocardial ischemia and/or infarction. Ventricularfibrillation often occurs in the setting of acute myocardial ischemia,before infarction fully develops. At present, there is no satisfactorypharmacotherapy for the treatment and/or prevention of ventricularfibrillation during acute ischemia. In fact, many Class I antiarrhythmiccompounds may actually increase mortality in patients who have had amyocardial infarction.

Class Ia, Ic and III antiarrhythmic drugs have been used to convertrecent onset AF to sinus rhythm and prevent recurrence of the arrhythmia(Fuch and Podrid, 1992; Nattel S., Hadjis T., Talajic M., Drugs48(3):345-71, 1994). However, drug therapy is often limited by adverseeffects, including the possibility of increased mortality, andinadequate efficacy (Feld G. K., Circulation. 83(6):2248-50, 1990;Coplen S. E., Antman E. M., Berlin J. A., Hewitt P., Chalmers T. C.,Circulation 1991; 83(2):714 and Circulation 82(4):1106-16, 1990; FlakerG. C., Blackshear J. L., McBride R., Kronmal R. A., Halperin J. L., HartR. G., Journal of the American College of Cardiology 20(3):527-32, 1992;CAST, N. Engl. J. Med. 321:406, 1989; Nattel S., CardiovascularResearch. 37(3):567-77, 1998). Conversion rates for Class Iantiarrhythmics range between 50-90% (Nattel S., Hadjis T., Talajic M.,Drugs 48(3):345-71, 1994; Steinbeck G., Remp T., Hoffmann E., Journal ofCardiovascular Electrophysiology. 9(8 Suppl):S104-8, 1998). Class IIIantiarrhythmics appear to be more effective for terminating atrialflutter than for AF and are generally regarded as less effective thanClass I drugs for terminating of AF (Nattel S., Hadjis T., Talajic M.,Drugs. 48(3):345-71, 1994; Capucci A., Aschieri D., Villani G. Q., Drugs& Aging 13(1):51-70, 1998). Examples of such drugs include ibutilide,dofetilide and sotalol. Conversion rates for these drugs range between30-50% for recent onset AF (Capucci A., Aschieri D., Villani G. Q.,Drugs & Aging 13(1):51-70, 1998), but they are also associated with arisk of inducing the ventricular tachyarrhythmias known as torsades depointes. For ibutilide, the risk of ventricular proarrhythmia isestimated at ˜4.4%, with ˜1.7% of patients requiring cardioversion forrefractory ventricular arrhythmias (Kowey P. R., VanderLugt J. T.,Luderer J. R., American Journal of Cardiology 78(8A):46-52, 1996). Suchevents are particularly tragic in the case of AF as this arrhythmia israrely a fatal in and of itself.

Therefore, there is a need in the art to identify new antiarrhythmictreatments, for both ventricular arrhythmias as well as for atrialarrhythmias. The present invention fulfills this need, and furtherprovides other related advantages.

BRIEF SUMMARY OF THE INVENTION

As disclosed within the present invention, a variety of cardiacpathological conditions may be treated and/or prevented by the use ofone or more ion channel modulating compounds that either singly ortogether with one or more additional compounds are able to selectivelyinhibit certain combination of cardiac ionic currents. Morespecifically, the cardiac currents referred to above are the sodiumcurrents and early repolarising currents.

Early repolarising currents correspond to those cardiac ionic currentswhich activate rapidly after depolarization of membrane voltage andwhich effect repolarisation of the cell. Many of these currents arepotassium currents and may include, but are not limited to, thetransient outward current I_(to 1) such as Kv4.2 and Kv4.3), and theultrarapid delayed rectifier current (I_(Kur)) such as Kv1.5, Kv1.4 andKv2.1). The ultrarapid delayed rectifier current (I_(Kur)) has also beendescribed as I_(sus). A second calcium dependent transient outwardcurrent (I_(to 2)) has also been described.

The cardiac pathological conditions that may be treated and/or preventedby the present invention may include, but are not limited to,arrhythmias such as the various types of atrial and ventriculararrhythmias.

In one embodiment, the present invention provides ion channel modulatingcompounds that can be used to selectively inhibit cardiac earlyrepolarising currents and cardiac sodium currents.

In another embodiment, the present invention provides ion channelmodulating compounds that can be used to selectively inhibit cardiacearly repolarising currents and cardiac sodium currents under conditionswhere an “arrhythmogenic substrate” is present in the heart. An“arrhythmogenic substrate” is characterized by a reduction in cardiacaction potential duration and/or changes in action potential morphology,premature action potentials, high heart rates and may also includeincreased variability in the time between action potentials and anincrease in cardiac milieu acidity due to ischaemia or inflammation.Changes such as these are observed during conditions of myocardialischaemia or inflammation and those conditions that precede the onset ofarrhythmias such as atrial fibrillation.

In another embodiment, the present invention provides aminocyclohexylether compounds of formula (I), or a solvate or pharmaceuticallyacceptable salt thereof:

wherein, independently at each occurrence,

X is selected from a direct bond, —C(R₆,R₁₄)—Y— and —C(R₁₃)═CH—, withthe proviso that when X is a direct bond and A is formula (III) then atleast one of R₇, R₈ and R₉ is not hydrogen;

Y is selected from a direct bond, O, S and C₁-C₄alkylene;

R₁₃ is selected from hydrogen, C₁-C₆alkyl, C₃-C₈cycloalkyl, aryl andbenzyl;

R₁ and R₂ are independently selected from hydrogen, C₁-C₈alkyl,C₃-C₈alkoxyalkyl, C₁-C₈hydroxyalkyl, and C₇-C₁₂aralkyl; or

R₁ and R₂, when taken together with the nitrogen atom to which they aredirectly attached in formula (I), form a ring denoted by formula (II):

wherein the ring of formula (II) is formed from the nitrogen as shown aswell as three to nine additional ring atoms independently selected fromcarbon, nitrogen, oxygen, and sulfur; where any two adjacent ring atomsmay be joined together by single or double bonds, and where any one ormore of the additional carbon ring atoms may be substituted with one ortwo substituents selected from hydrogen, hydroxy, C₁-C₃hydroxyalkyl,oxo, C₂-C₄acyl, C₁-C₃alkyl, C₂-C₄alkylcarboxy, C₁-C₃alkoxy,C₁-C₂₀alkanoyloxy, or may be substituted to form a spiro five- orsix-membered heterocyclic ring containing one or two heteroatomsselected from oxygen and sulfur; and any two adjacent additional carbonring atoms may be fused to a C₃-C₈-carbocyclic ring, and any one or moreof the additional nitrogen ring atoms may be substituted withsubstituents selected from hydrogen, C₁-C₆alkyl, C₂-C₄acyl,C₂-C₄hydroxyalkyl and C₃-C₈alkoxyalkyl; or

R₁ and R₂, when taken together with the nitrogen atom to which they aredirectly attached in formula (I), may form a bicyclic ring systemselected from 3-azabicyclo[3.2.2]nonan-3-yl,2-azabicyclo[2.2.2]octan-2-yl, 3-azabicyclo[3.1.0]-hexan-3-yl and3-azabicyclo[3.2.0]heptan-3-yl;

R₃ and R₄ are independently attached to the cyclohexane ring shown informula (I) at the 3-, 4-, 5- or 6-positions and are independentlyselected from hydrogen, hydroxy, C₁-C₆alkyl and C₁-C₆alkoxy, and, whenboth R₃ and R₄ are attached to the same cyclohexane ring atom, maytogether form a spiro five- or six-membered heterocyclic ring containingone or two heteroatoms selected from oxygen and sulfur;

R₅, R₆ and R₁₄ are independently selected from hydrogen, C₁-C₆alkyl,aryl and benzyl, or R₆ and R₁₄, when taken together with the carbon towhich they are attached, may form a spiro C₃-C₅cycloalkyl;

A is selected from C₅-C₁₂alkyl, a C₃-C₁₃-carbocyclic ring, and ringsystems selected from formulae (III), (IV), (V), (VI), (VII) and (VIII):

where R₇, R₈ and R₉ are independently selected from bromine, chlorine,fluorine, carboxy, hydrogen, hydroxy, hydroxymethyl, methanesulfonamido,nitro, sulfamyl, trifluoromethyl, C₂-C₇alkanoyloxy, C₁-C₆alkyl,C₁-C₆alkoxy, C₂-C₇alkoxycarbonyl, C₁-C₆thioalkyl and N(R₁₅,R₁₆) whereR₁₅ and R₁₆ are independently selected from hydrogen, acetyl,methanesulfonyl and C₁-C₆alkyl;

where R₁₀ and R₁₁ are independently selected from bromine, chlorine,fluorine, carboxy, hydrogen, hydroxy, hydroxymethyl, methanesulfonamido,nitro, sulfamyl, trifluoromethyl, C₂-C₇alkanoyloxy, C₁-C₆alkyl,C₁-C₆alkoxy, C₂-C₇alkoxycarbonyl, C₁-C₆thioalkyl, and N(R₁₅,R₁₆) whereR₁₅ and R₁₆ are independently selected from hydrogen, acetyl,methanesulfonyl, and C₁-C₆alkyl;

where R₁₂ is selected from bromine, chlorine, fluorine, carboxy,hydrogen, hydroxy, hydroxymethyl, methanesulfonamido, nitro, sulfamyl,trifluoromethyl, C₂-C₇alkanoyloxy, C₁-C₆alkyl, C₁-C₆alkoxy,C₂-C₇alkoxycarbonyl, C₁-C₆thioalkyl, and N(R₁₅,R₁₆) where R₁₅ and R₁₆are independently selected from hydrogen, acetyl, methanesulfonyl, andC₁-C₆alkyl; and Z is selected from CH, CH₂, O, N and S, where Z may bedirectly bonded to “X” as shown in formula (I) when Z is CH or N, or Zmay be directly bonded to R₁₇ when Z is N, and R₁₇ is selected fromhydrogen, C₁-C₆alkyl, C₃-C₈cycloalkyl, aryl and benzyl;

including isolated enantiomeric, diastereomeric and geometric isomersthereof, and mixtures thereof.

In other embodiments, the present invention provides a composition ormedicament that includes a compound according to formula (I) incombination with a pharmaceutically acceptable carrier, diluent orexcipient, and further provides a method for the manufacture of acomposition or medicament that contains a compound according to formula(I).

In other embodiments, the present invention provides pharmaceuticalcompositions that contain at least one compound of formula (I) in anamount effective to treat a disease or condition in a warm-bloodedanimal suffering from or having the disease or condition, and/or preventa disease or condition in a warm-blooded animal that would otherwiseoccur, and further contains at least one pharmaceutically acceptablecarrier, diluent or excipient. The invention further provides formethods of treating a disease or condition in a warm-blooded animalsuffering from or having the disease or condition, and/or preventing adisease or condition from arising in a warm-blooded animal, wherein atherapeutically effective amount of a compound of formula (I), or acomposition containing a compound of formula (I) is administered to awarm-blooded animal in need thereof. The diseases and conditions towhich the compounds, compositions and methods of the present inventionhave applicability are as follows: arrhythmia, diseases of the centralnervous system, convulsion, epileptic spasms, depression, anxiety,schizophrenia, Parkinson's disease, respiratory disorders, cysticfibrosis, asthma, cough, inflammation, arthritis, allergies,gastrointestinal disorders, urinary incontinence, irritable bowelsyndrome, cardiovascular diseases, cerebral or myocardial ischemias,hypertension, long-QT syndrome, stroke, migraine, ophthalmic diseases,diabetes mellitus, myopathies, Becker's myotonia, myasthenia gravis,paramyotonia congentia, malignant hyperthermia, hyperkalemic periodicparalysis, Thomsen's myotonia, autoimmune disorders, graft rejection inorgan transplantation or bone marrow transplantation, heart failure,hypotension, Alzheimer's disease or other metal disorder, and alopecia.

In another embodiment, the present invention provides a pharmaceuticalcomposition containing an amount of a compound of formula (I) effectiveto produce local analgesia or anesthesia in a warm-blooded animal inneed thereof, and a pharmaceutically acceptable carrier, diluent, orexcipient. The invention further provides a method for producing, localanalgesia or anesthesia in a warm-blooded animal which includesadministering to a warm-blooded animal in need thereof an effectiveamount of a compound of formula (I) or a pharmaceutical compositioncontaining a compound of formula (I). These compositions and methods maybe used to relieve or forestall the sensation of pain in a warm-bloodedanimal.

In another embodiment, the present invention provides a pharmaceuticalcomposition containing an amount of a compound of formula (I) effectiveto enhance the libido in a warm-blooded animal in need thereof, and apharmaceutically acceptable carrier, diluent, or excipient. Theinvention further provides a method for enhancing libido in awarm-blooded animal which includes administering to a warm-bloodedanimal in need thereof an effective amount of a compound of formula (I)or a pharmaceutical composition containing a compound of formula (I).These compositions and methods may be used, for example, to treat asexual dysfunction, e.g., impotence in males, and/or to enhance thesexual desire of a patient without a sexual dysfunction. As anotherexample, the therapeutically effective amount may be administered to abull (or other breeding stock), to promote increased semen ejaculation,where the ejaculated semen is collected and stored for use as it isneeded to impregnate female cows in promotion of a breeding program.

In another embodiment, the present invention provides a compound offormula (I) or composition containing a compound of formula (I), for usein methods for either modulating ion channel activity in a warm-bloodedanimal or for modulating ion channel activity in vitro.

These and other embodiments of the present invention will become evidentupon reference to the following drawings and detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates the reaction sequence further described in Example 1,for preparing an aminocyclohexyl ether compound of the presentinvention.

FIG. 2 illustrates a procedure whereby either cis- ortrans-aminocyclohexyl ether compounds of the present invention may beprepared.

FIG. 3 illustrates synthetic methodology that may be employed to prepareeither cis or trans stereoisomers of the compounds of the presentinvention.

FIGS. 4A and 4B illustrate the synthetic methodology described inExample 15.

DETAILED DESCRIPTION OF THE INVENTION

As briefly noted above, in one aspect the present invention provides forthe treatment and/or prevention of a variety of cardiac pathologicalconditions by the use of one or more ion channel modulating compoundsthat either singly, or together with one or more additional compounds,are able to inhibit selective cardiac ionic currents. More specifically,the cardiac currents referred to above are the sodium currents and earlyrepolarising currents.

Early repolarising currents correspond to those cardiac ionic currentswhich activate rapidly after depolarisation of membrane voltage andwhich effect repolarisation of the cell. Many of these currents arepotassium currents and may include, but are not limited to, thetransient outward current (I_(to 1) such as Kv4.2 and Kv4.3), and theultrarapid delayed rectifier current (I_(Kur) such as Kv1.5, Kv1.4, andKv2.1). The ultrarapid delayed rectifier current (I_(Kur)) has also bedescribed as I_(sus). A second calcium dependent transient outwardcurrent (I_(to 2)) has also been described.

The cardiac pathological conditions that may be treated and/or preventedby the novel methods of the present invention may include, but are notlimited to, arrhythmias such as the various types of atrial(supraventricular) and ventricular arrhythmias. The compounds of thepresent invention are especially useful in treating and/or preventingatrial fibrillation and ventricular fibrillation.

The novel methods of the present invention are especially useful underconditions where an “arrhythmogenic substrate” is present in the heart.An “arrhythmogenic substrate” is characterized by a reduction in cardiacaction potential duration and/or changes in action potential morphology,premature action potentials, high heart rates and may also includeincreased variability in the time between action potentials and anincrease in cardiac milieu acidity due to ischaemia or inflammation.Changes such as these are observed during conditions of myocardialischaemia or inflammation (Janse & Wit, Physiol. Rev. 69(4):1049-169,October 1989), and those conditions that precede the onset ofarrhythmias such as atrial fibrillation (Pichlmaier et al. Heart80(5):467-72, November 1998). Under conditions described above forcardiac arrhythmias in general, there is an increase in acidity of thecardiac milieu from the normal physiological pH (i.e., the pH of themilieu is lower than normal).

In the novel methods of the present invention of treating and/orpreventing arrhythmia, one or more ion channel modulating compounds,either singly or together, are used to inhibit selective cardiac sodiumcurrents and cardiac early repolarising currents. It is preferable thatthe ion channel modulating compounds generally have a pKa value of about4 to 9 and more preferably less than about 8. The most preferred pKavalues are between about 5 and 7.5. Methods to determine pKa values arewell known in the art (see, e.g., Perrin, “Dissociation Constants ofOrganic Bases in Aqueous Solution”, Butterworth, London, 1972). Forcompounds of the present invention with a preferred pKa value, thefraction of the charged (protonated) species will be increased under thepathological conditions such as cardiac arrhythmias and the presence ofan arrhythmogenic substrate in the heart as described above due to theincrease in cardiac milieu acidity. Where the charged form of a compoundis active, its potency increases under conditions associated with anincreases in cardiac milieu acidity.

In other methods of the present invention of treating and/or preventingarrhythmia, one or more ion channel modulating compounds, either singlyor together with one or more additional compounds, are used to inhibitselective cardiac ionic currents. More specifically, the cardiaccurrents referred to above are the sodium currents and earlyrepolarising currents. It is preferable that the ion channel modulatingcompounds block the said cardiac currents from extracellular loci. Suchcompounds act on an external locus of the ion channel that is accessiblefrom the extracellular surface. This facilitates access to the ionchannel and provides rapid onset kinetics and exhibits frequencydependent blockade of currents. Such properties are all beneficial forcompounds used to treat arrhythmias.

The novel methods of the present invention provide treatment and/orprevention of arrhythmias that do not prolong action potential durationin normal cardiac ventricle but rather prolongs action potentialduration under conditions when an arrhythmogenic substrate is present inthe heart. Blockade of early, rather than late repolarising currentswill prolong action potential duration under conditions where actionpotential duration has been previously reduced. Blockade of early,rather than late, repolarising currents offers another advantage overexisting methods. Blockade of late repolarising currents such as I_(Kr)(HERG) and I_(Ks) (minK-LQT) prolongs action potential under normalconditions. In so doing there is a risk of precipitating a polymorphicventricular tachycardia commonly called torsade de pointes which can befatal (Nattel, 1998). As blockade of early repolarising currents doesnot prolong action potential duration under normal conditions, the novelmethods of the present invention greatly reduce such proarrhythmia risk.

Methods for in vitro assessment of inhibition activity of ion channelmodulating compounds on different cardiac ion currents are well known inthe art and are briefly described in Example 33 below.

Methods for assessment of proarrhythmia (e.g., torsade de pointes) riskof ion channel modulating compounds are also published in the literatureand are briefly described in Example 34 below.

In the novel methods of the present invention of treating and/orpreventing arrhythmia, one or more ion channel modulating compounds,either singly or together, are used to inhibit selective cardiac sodiumcurrents and cardiac early repolarising currents. The concentration ofeach compound is typically between 0.001 and 30 μM.

Thus, the present invention is directed to ion channel modulatingcompounds that block cardiac early repolarising currents and cardiacsodium currents. The ion channel modulating compounds block the cardiacion channels responsible for early repolarising currents and sodiumcurrents; and/or block cardiac early repolarising currents and cardiacsodium currents under conditions where an arrhythmogenic substrate ispresent in the heart; and/or block the cardiac ion channels responsiblefor early repolarising currents and sodium currents under conditionswhere an arrhythmogenic substrate is present in the heart; and/or blockcardiac early repolarising currents and cardiac sodium currents fromextracellular loci in cardiac cells; and/or have pKa values of between4-9, preferably having have pKa values of between 5-7.5.

In one embodiment, the cardiac early repolarising currents referred toabove comprise ionic currents which activate rapidly afterdepolarisation of membrane voltage and which effect repolarisation ofthe cell. The early repolarising currents may comprise the cardiactransient outward potassium current (I_(to)) and/or the ultrarapid delayrectifier current (I_(Kur)). The cardiac transient outward potassiumcurrent (I_(to)) and/or the ultrarapid delay rectifier current (I_(Kur))may comprise at least one of the Kv4.2, Kv4.3, Kv2.1, Kv1.4 and Kv1.5currents.

The invention also provides a composition comprising one or more of theabove-described ion channel modulating compounds in combination with apharmaceutically acceptable carrier, excipient or diluent.

The present invention provides that the above-described ion channelmodulating compound(s) and/or composition(s) containing same may be usedin a method for treating or preventing arrhythmia in a warm-bloodedanimal; and/or may be used in a method for modulating ion channelactivity in a warm-blooded animal; and/or may be used in a method formodulating ion channel activity in vitro.

The invention also provides for the use of an ion channel modulatingcompound in a manufacture of a medicament.

The invention further provides a pharmaceutical composition comprising(a) an amount of an ion modulating compound as described above effectiveto treat or prevent atrial arrhythmia in a warm-blooded animal in needof the treatment or prevention, and (b) a pharmaceutically acceptablecarrier, diluent, or excipient. According to the present invention, thiscomposition may be used in a method for treating or preventing atrialarrhythmia in a warm-blooded animal, where the method comprisesadministering to a warm-blooded animal in need thereof a therapeuticallyeffective amount of one of the above-described ion channel modulatingcompounds or a composition containing same.

The invention further provides a pharmaceutical composition comprising(a) an amount of an ion channel modulating compound as described aboveeffective to treat or prevent ventricular arrhythmia in a warm-bloodedanimal in need of the treatment or prevention, and (b) apharmaceutically acceptable carrier, diluent, or excipient. Thiscomposition may be used in a method for treating or preventingventricular arrhythmia in a warm-blooded animal, where the methodcomprises administering to a warm-blooded animal in need thereof atherapeutically effective amount of one of the above-described ionchannel modulating compounds or a composition containing same.

The invention further provides a method for inhibiting multiple cardiacionic current, where the method comprises administering to awarm-blooded animal in need thereof one or more compounds that eithersingly or together both block cardiac early repolarising currents andcardiac sodium currents, said one or more compounds being administeredin an amount effective to block cardiac sodium currents and cardiacearly repolarising currents. In this method, said one or more compoundsmay either singly or together both block cardiac early repolarisingcurrents and cardiac sodium currents from extracellular loci in cardiaccells.

The present invention also provides a method for inhibiting multiplecardiac ionic currents, where the method comprises administering to awarm-blooded animal in need thereof one or more compounds that eithersingly or together both block the cardiac ion channels responsible forearly repolarising currents and sodium channels, said one or morecompounds being administered in an amount effective to block the cardiacsodium ion channels and the cardiac early repolarising ion channels. Inthis method, said one or more compounds may either singly or togetherboth block cardiac ion channels responsible for early repolarisingcurrents and sodium currents from extracellular loci in cardiac cells.Also in this method one compound may block both sodium currents andcardiac early repolarising currents from extracellular loci in cardiaccells. Also in these methods, each of said one or more compounds mayhave a pKa value of less than 8.

The invention in addition provides a method for treating or preventing acardiac condition wherein there is an “arrhythmogenic substrate” presentin the heart, where the method comprises administering to a warm-bloodedanimal in need thereof, in an amount effective to treat or prevent saidcardiac condition, one or more compounds that either singly or togetherblock cardiac early repolarising currents and cardiac sodium currents.In this method, said one or more compounds may either singly or togetherboth block cardiac early repolarising currents and cardiac sodiumcurrents from extracellular loci in cardiac cells. Also in this method,one compound may both block cardiac early repolarising currents andcardiac sodium currents from extracellular loci in cardiac cells. Alsoin these methods, each of said one or more compounds may have a pKavalue of less than 8.

Furthermore, the present invention provides a method for treating orpreventing a cardiac condition wherein there is an “arrhythmogenicsubstrate” present in the heart, where this method comprisesadministering to a warm-blooded animal in need thereof, in an amounteffective to treat or prevent said cardiac condition, one or morecompounds that either singly or together both block cardiac ion channelsresponsible for early repolarising currents and sodium currents. In thismethod, said one or more compounds may either singly or together bothblock cardiac ion channels responsible for early repolarising currentsand sodium currents from extracellular loci in cardiac cells. Also inthis method, one compound may both block cardiac ion channelsresponsible for early repolarising currents and sodium currents fromextracellular loci in cardiac cells. Additionally in this method, eachof said one or more compounds may have a pKa value of less than 8.

The present invention provides a method for treating or preventing acardiac condition wherein there is an increase in acidity from thenormal physiological pH of the cardiac milieu, where the methodcomprises administering to a warm-blooded animal in need thereof, in anamount effective to treat or prevent said cardiac condition, one or morecompounds that either singly or together both block cardiac earlyrepolarising currents and cardiac sodium currents. In this method, saidone or more compounds may either singly or together both block cardiacion channels responsible for early repolarising currents and sodiumcurrents from extracellular loci in cardiac cells. Also in this method,one compound may block cardiac ion channels responsible for earlyrepolarising currents and in addition block sodium currents fromextracellular loci in cardiac cells. In this method, each of said one ormore compounds may have a pKa value of less than 8.

The present invention also provides a method for treating or preventinga cardiac condition wherein there is an increase in acidity from thenormal physiological pH of the cardiac milieu, where the methodcomprises administering to a warm-blooded animal in need thereof, in anamount effective to treat or prevent said cardiac condition, one or morecompounds that either singly or together both block cardiac ion channelsresponsible for early repolarising currents and sodium currents. In thismethod, said one or more compounds may either singly or together bothblock cardiac ion channels responsible for early repolarising currentsand sodium currents from extracellular loci in cardiac cells. Also inthis method, one compound may both block cardiac ion channelsresponsible for early repolarising currents and sodium currents fromextracellular loci in cardiac cells. Additionally, in this method, eachof said one or more compounds may have a pKa value of less than 8.

In a preferred embodiment, in the above-described methods, the cardiaccondition is ventricular arrhythmia. In another preferred embodiment, inthe above-described methods, the cardiac condition is atrial arrhythmia.In some instances, the increase in acidity of the cardiac milieu is dueto myocardial ischaemia. Additionally, or alternatively, the increase inacidity of the cardiac milieu is due to high heart rate. Additionally,or alternatively, the increase in acidity is due to inflammation.Additionally, or alternatively, the increase in acidity is due to thepresence of an “arrhythmogenic substrate” in the heart. Additionally, oralternatively, the increase in acidity is due to conditions whichprecede atrial fibrillation.

In another aspect, the present invention is directed to aminocyclohexylether compounds, pharmaceutical compositions containing theaminocyclohexyl ether compounds, and various uses for the compound andcompositions. Such uses include blockage of ion channels in vitro or invivo, the treatment of arrhythmias, the production of anesthesia, andother uses as described herein. An understanding of the presentinvention may be aided by reference to the following definitions andexplanation of conventions used herein.

DEFINITIONS AND CONVENTIONS

The aminocyclohexyl ether compounds of the invention have an etheroxygen atom at position 1 of a cyclohexane ring, and an amine nitrogenatom at position 2 of the cyclohexane ring, with other positionsnumbered in corresponding order as shown below in structure (A):

The bonds from the cyclohexane ring to the 1-oxygen and 2-nitrogen atomsin the above formula may be relatively disposed in either a cis or transrelationship. In a preferred embodiment of the present invention, thestereochemistry of the amine and ether substituents of the cyclohexanering is either (R,R)-trans or (S,S)-trans. In another preferredembodiment the stereochemistry is either (R,S)-cis or (S,R)-cis.

In the formulae depicted herein, a bond to a substituent and/or a bondthat links a molecular fragment to the remainder of a compound may beshown as intersecting one or more bonds in a ring structure. Thisindicates that the bond may be attached to any one of the atoms thatconstitutes the ring structure, so long as a hydrogen atom couldotherwise be present at that atom. Where no particular substituent(s) isidentified for a particular position in a structure, then hydrogen(s) ispresent at that position. For example, compounds of the inventioncontaining the A-X—CH(R₅)— group where A equals formula (III)

are intended to encompass compounds having the group (B):

where the group (B) is intended to encompass groups wherein any ringatom that could otherwise be substituted with hydrogen, may instead besubstituted with either R₇, R₈ or R₉, with the proviso that each of R₇,R₈ and R₉ appears once and only once on the ring. Ring atoms that arenot substituted with any of R₇, R₈ or R₉ are substituted with hydrogen.In those instances where the invention specifies that a non-aromaticring is substituted with more than one R group, and those R groups areshown connected to the non-aromatic ring with bonds that bisect ringbonds, then the R groups may be present at different atoms of the ring,or on the same atom of the ring, so long as that atom could otherwise besubstituted with a hydrogen atom.

Likewise, where the invention specifies compounds containing theA-X—CH(R₅)— group where A equals the aryl group (VI)

the invention is intended to encompass compounds wherein —X—CH(R₅)— isjoined through X to the aryl group (VI) at any atom which forms the arylgroup (VI) so long as that atom of group (VI) could otherwise besubstituted with a hydrogen atom. Thus, there are seven positions(identified with the letters “a” through “g”) in structure (VI) wherethe —X—CH(R₅)— group could be attached, and it is attached at one ofthose seven positions. The R₁₂ group would occupy one and only one ofthe remaining six positions, and hydrogen atoms would be present in eachof the five remaining positions. It is to be understood that when Zrepresents a divalent atom, e.g., oxygen or sulfur, then Z cannot bedirectly bonded to —X—CH(R₅)—.

When the invention specifies the location of an asymmetric divalentradical, then that divalent radical may be positioned in any possiblemanner that provides a stable chemical structure. For example, forcompounds containing the A-X—CH(R₅)— group where X is C(R₁₄,R₆)—Y—, theinvention provides compounds having both the A-C(R₁₄,R₆)—Y—CH(R₅)— andA-Y—C(R₁₄,R₆)—CH(R₅)— groups.

A wavy bond from a substituent to the central cyclohexane ring indicatesthat that group may be located on either side of the plane of thecentral ring.

The compounds of the present invention contain at least two asymmetriccarbon atoms and thus exist as enantiomers and diastereomers. Unlessotherwise noted, the present invention includes all enantiomeric anddiastereomeric forms of the aminocyclohexyl ether compounds of theinvention. Pure stereoisomers, mixtures of enantiomers and/ordiastereomers, and mixtures of different compounds of the invention areincluded within the present invention. Thus, compounds of the presentinvention may occur as racemates, racemic mixtures and as individualdiastereomers, or enantiomers with all isomeric forms being included inthe present invention. A racemate or racemic mixture does not imply a50:50 mixture of stereoisomers.

The phrase “independently at each occurrence” is intended to mean (i)when any variable occurs more than one time in a compound of theinvention, the definition of that variable at each occurrence isindependent of its definition at every other occurrence; and (ii) theidentity of any one of two different variables (e.g., R₁ within the setR₁ and R₂) is selected without regard the identity of the other memberof the set. However, combinations of substituents and/or variables arepermissible only if such combinations result in stable compounds.

In accordance with the present invention and as used herein, thefollowing terms are defined to have following meanings, unlessexplicitly stated otherwise:

“Acid addition salts” refers to those salts which retain the biologicaleffectiveness and properties of the free bases and which are notbiologically or otherwise undesirable, formed with inorganic acids suchas hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid,phosphoric acid and the like, or organic acids such as acetic acid,propionic acid, glycolic acid, pyruvic acid, oxalic acid, maleic acid,malonic acid, succinic acid, fumaric acid, tartaric acid, citric acid,benzoic acid, cinnamic acid, mandelic acid, methanesulfonic acid,ethanesulfonic acid, p-toluenesulfonic acid, salicylic acid and thelike.

“Acyl” refers to branched or unbranched hydrocarbon fragments terminatedby a carbonyl —(C═O)— group containing the specified number of carbonatoms. Examples include acetyl [CH₃C═O—, a C₂acyl] and propionyl[CH₃CH₂C═O—, a C₃acyl].

“Alkanoyloxy” refers to an ester substituent wherein the ether oxygen isthe point of attachment to the molecule. Examples include propanoyloxy[(CH₃CH₂C═O—O—, a C₃alkanoyloxy] and ethanoyloxy [CH₃C═O—O—, aC₂alkanoyloxy].

“Alkoxy” refers to an O-atom substituted by an alkyl group, for example,methoxy [—OCH₃, a C₁alkoxy].

“Alkoxyalkyl” refers to a alkylene group substituted with an alkoxygroup. For example, methoxyethyl [CH₃OCH₂CH₂—] and ethoxymethyl(CH₃CH₂OCH₂—] are both C₃alkoxyalkyl groups.

“Alkoxycarbonyl” refers to an ester substituent wherein the carbonylcarbon is the point of attachment to the molecule. Examples includeethoxycarbonyl [CH₃CH₂OC═O—, a C₃alkoxycarbonyl] and methoxycarbonyl[CH₃OC═O—, a C₂alkoxycarbonyl].

“Alkyl” refers to a branched or unbranched hydrocarbon fragmentcontaining the specified number of carbon atoms and having one point ofattachment. Examples include n-propyl (a C₃alkyl), iso-propyl (also aC₃alkyl), and t-butyl (a C₄alkyl).

“Alkylene” refers to a divalent radical which is a branched orunbranched hydrocarbon fragment containing the specified number ofcarbon atoms, and having two points of attachment. An example ispropylene [—CH₂CH₂CH₂—, a C₃alkylene].

“Alkylcarboxy” refers to a branched or unbranched hydrocarbon fragmentterminated by a carboxylic acid group [—COOH]. Examples includecarboxymethyl [HOOC—CH₂—, a C₂alkylcarboxy] and carboxyethyl[HOOC—CH₂CH₂—, a C₃alkylcarboxy].

“Aryl” refers to aromatic groups which have at least one ring having aconjugated pi electron system and includes carbocyclic aryl,heterocyclic aryl (also known as heteroaryl groups) and biaryl groups,all of which may be optionally substituted. Carbocyclic aryl groups aregenerally preferred in the compounds of the present invention, wherephenyl and naphthyl groups are preferred carbocyclic aryl groups.

“Aralkyl” refers to an alkylene group wherein one of the points ofattachment is to an aryl group. An example of an aralkyl group is thebenzyl group [C₆H₅CH₂—, a C₇aralkyl group].

“Cycloalkyl” refers to a ring, which may be saturated or unsaturated andmonocyclic, bicyclic, or tricyclic formed entirely from carbon atoms. Anexample of a cycloalkyl group is the cyclopentenyl group (C₅H₇—), whichis a five carbon (C₅) unsaturated cycloalkyl group.

“Carbocyclic” refers to a ring which may be either an aryl ring or acycloalkyl ring, both as defined above.

“Carbocyclic aryl” refers to aromatic groups wherein the atoms whichform the aromatic ring are carbon atoms. Carbocyclic aryl groups includemonocyclic carbocyclic aryl groups such as phenyl, and bicycliccarbocyclic aryl groups such as naphthyl, all of which may be optionallysubstituted.

“Heteroatom” refers to a non-carbon atom, where boron, nitrogen, oxygen,sulfur and phosphorus are preferred heteroatoms, with nitrogen, oxygenand sulfur being particularly preferred heteroatoms in the compounds ofthe present invention.

“Heteroaryl” refers to aryl groups having from 1 to 9 carbon atoms andthe remainder of the atoms are heteroatoms, and includes thoseheterocyclic systems described in “Handbook of Chemistry and Physics,”49th edition, 1968, R. C. Weast, editor; The Chemical Rubber Co.,Cleveland, Ohio. See particularly Section C, Rules for Naming OrganicCompounds, B. Fundamental Heterocyclic Systems. Suitable heteroarylsinclude furanyl, thienyl, pyridyl, pyrrolyl, pyrimidyl, pyrazinyl,imidazolyl, and the like.

“Hydroxyalkyl” refers to a branched or unbranched hydrocarbon fragmentbearing an hydroxy (—OH) group. Examples include hydroxymethyl (—CH₂OH,a C₁hydroxyalkyl) and 1-hydroxyethyl (—CHOHCH₃, a C₂hydroxyalkyl).

“Thioalkyl” refers to a sulfur atom substituted by an alkyl group, forexample thiomethyl (CH₃S—, a C₁thioalkyl).

“Modulating” in connection with the activity of an ion channel meansthat the activity of the ion channel may be either increased ordecreased in response to administration of a compound or composition ormethod of the present invention. Thus, the ion channel may be activated,so as to transport more ions, or may be blocked, so that fewer or noions are transported by the channel.

“Pharmaceutically acceptable carriers” for therapeutic use are wellknown in the pharmaceutical art, and are described, for example, inRemingtons Pharmaceutical Sciences, Mack Publishing Co. (A. R. Gennaroedit. 1985). For example, sterile saline and phosphate-buffered salineat physiological pH may be used. Preservatives, stabilizers, dyes andeven flavoring agents may be provided in the pharmaceutical composition.For example, sodium benzoate, sorbic acid and esters of p-hydroxybenzoicacid may be added as preservatives. Id. at 1449. In addition,antioxidants and suspending agents may be used. Id.

“Pharmaceutically acceptable salt” refers to salts of the compounds ofthe present invention derived from the combination of such compounds andan organic or inorganic acid (acid addition salts) or an organic orinorganic base (base addition salts). The compounds of the presentinvention may be used in either the free base or salt forms, with bothforms being considered as being within the scope of the presentinvention.

The “therapeutically effective amount” of a compound of the presentinvention will depend on the route of administration, the type ofwarm-blooded animal being treated, and the physical characteristics ofthe specific warm-blooded animal under consideration. These factors andtheir relationship to determining this amount are well known to skilledpractitioners in the medical arts. This amount and the method ofadministration can be tailored to achieve optimal efficacy but willdepend on such factors as weight, diet, concurrent medication and otherfactors which those skilled in the medical arts will recognize.

Compositions described herein as “containing a compound of formula (I)”encompass compositions that contain more than one compound of formula(I).

Compounds of the Present Invention

The compounds of the present invention are amines which may berepresented by formula (I):

Compounds of formula (I) are aminocyclohexyl ethers. More specifically,these aminocyclohexyl ethers are substituted at position 2 of thecyclohexyl ring with an amine group —NR₁R₂. The cyclohexyl ring may alsobe substituted with additional substituents (designated as R₃ and R₄) asdescribed in more detail below. Examples of specific embodiments ofcompounds represented by formula (I) are described below

Depending upon the selection of substituents R₁ and R₂, the compounds offormula (I) may be primary, secondary, or tertiary amines (i.e., both R₁and R₂ are hydrogen, only one of R₁ and R₂ is hydrogen, or neither of R₁and R₂ are hydrogen, respectively). In one embodiment of the invention,the compounds of formula (I) are tertiary amines, i.e., neither R₁ norR₂ is hydrogen. Where the amine is tertiary, it may be a cyclic amine.Amine substituents R₁ and R₂ may be independently selected fromsubstituents which include hydrogen, alkyl groups containing from one toeight carbon atoms (i.e., C₁-C₈alkyl), alkoxyalkyl groups containingfrom three to eight carbon atoms (i.e., C₃-C₈alkoxyalkyl), alkyl groupscontaining from one to eight carbon atoms where one of the carbon atomsis substituted with a hydroxyl group (i.e., C₁-C₈hydroxyalkyl), andaralkyl groups containing from seven to twelve carbon atoms (i.e.,C₇-C₁₂aralkyl).

Alternatively, R₁ and R₂, when taken together with the nitrogen atom towhich they are directly attached in formula (I), may form a ring denotedby formula (II):

wherein the ring of formula (II) is formed from the nitrogen as shown aswell as three to nine additional ring atoms independently selected fromcarbon, nitrogen, oxygen, and sulfur; where any two adjacent ring atomsmay be joined together by single or double bonds, and where any one ormore of the additional carbon ring atoms may be substituted with one ortwo substituents selected from hydrogen, hydroxy, C₁-C₃hydroxyalkyl,oxo, C₂-C₄acyl, C₁-C₃alkyl, C₂-C₄alkylcarboxy, C₁-C₃alkoxy,C₁-C₂₀alkanoyloxy, or may be substituted to form a spiro five- orsix-membered heterocyclic ring containing one or two heteroatomsselected from oxygen and sulfur (e.g., an acetal, thioacetal, ketal, orthioketal group); and any two adjacent additional carbon ring atoms maybe fused to a C₃-C₈-carbocyclic ring, and any one or more of theadditional nitrogen ring atoms may be substituted with substituentsselected from hydrogen, C₁-C₆alkyl, C₂-C₄acyl, C₂-C₄hydroxyalkyl andC₃-C₈alkoxyalkyl. Examples of substituents containing a fused ringsystem include the perhydroindolyl and 1,2,3,4-tetrahydroisoquinolinylgroups.

In connection with the ring of formula (II), any two adjacent ring atomsmay be joined together by single or double bonds. Thus, the ring offormula (II) may be saturated or unsaturated, and an unsaturated ringmay contain one, or more than one, sites of unsaturation. In otherwords, the ring of formula (II) may contain one or more double bonds, itbeing understood, however, that the unsaturated ring of formula (TI) ischemically stable.

Alternatively, R₁ and R₂, when taken together with the 2-amino nitrogenof formula (I), may complete a bicyclic ring. Bicyclic rings include,for example, 3-azabicyclo[3.2.2]nonane, 2-azabicyclo[2.2.2]octane,3-azabicyclo[3.1.0]hexane, and 3-azabicyclo[3.2.0]heptane. For thesederivatives, the 2-substituents of the cyclohexyl ethers of formula (I)are the following groups: 3-azabicyclo[3.2.2]nonan-3-yl,2-azabicyclo[2.2.2]octan-2-yl, 3-azabicyclo[3.1.0]hexan-3-yl, and3-azabicyclo[3.2.0]-heptan-3-yl.

Preferably, R₁ and R₂, when taken together, contain only a singleheteroatom. Preferred heteroatoms include nitrogen, oxygen and sulfur.An example of a ring in which R₁ and R₂ together include an oxygenheteroatom is the morpholinyl group. An example of a ring where R₁ andR₂ together include a second nitrogen heteroatom is the piperazinylgroup.

Cyclohexane substituents R₃ and R₄ may be independently attached to ringpositions 3, 4, 5 or 6 (i.e., both R₃ and R₄ may be attached to the samering position or each attached to different ring positions). R₃ and R₄are independently selected from hydrogen, hydroxy, C₁-C₆alkyl, andC₁-C₆alkoxy, and, when both R₃ and R₄ are attached to the samecyclohexane ring atom, may together form a spiro five- or six-memberedheterocyclic ring containing one or two heteroatoms selected from oxygenand sulfur. Preferred heterocyclic substituents contain either a singleoxygen or a single sulfur ring atom.

Depending upon the identity of X, the ether side chain, —CH(R₅)—X-A, informula (I) may take several forms. For example, a compound of formula(I) may have X as a —C(R₆,R₁₄)—Y— group, where Y may be any of a directbond, an oxygen atom (O), a sulfur atom (S) or a C₁-C₄alkylene group. R₆and R₁₄ are independently selected from hydrogen, C₁-C₆alkyl, aryl andbenzyl, or R₆ and R₁₄, when taken together with the carbon to which theyare attached, may form a spiro C₃-C₅cycloalkyl. Thus, compounds of theinvention include compounds of formula (I) where R₆ and R₁₄ are hydrogenand Y is a direct bond, such that X may be CH₂.

Alternatively, X may be an alkenylene moiety, e.g., a cis- ortrans-alkenylene moiety, C(R₁₃)═CH, where R₁₃ may be any of hydrogen,C₁-C₆alkyl, C₃-C₈cycloalkyl, aryl or benzyl. For compounds of formula(I) where X is an alkenylene moiety, X is preferably a trans-alkenylenemoiety.

Alternatively, X may be a direct bond. Independent of the selections forA, X and other variables, R₅ is selected from hydrogen, C₁-C₆alkyl, aryland benzyl.

In one embodiment of the present invention, X is either a —C(R₆,R₁₄)—Y—or a C(R₁₃)═CH group, and is not a direct bond. In another embodiment,the compounds of the invention exclude those compounds wherein X is adirect bond when R₁ and R₂ are hydrogen. In another embodiment, X isselected from a direct bond, —C(R₆,R₁₄)—Y—, and —C(R₁₃)═CH—, with theproviso that when X is a direct bond and A is formula (III) then atleast one of R₇, R₈ and R₉ is not hydrogen. In another embodiment, thecompounds of the invention exclude those compounds wherein X is a directbond when A is formula (III) and each of R₇, R₈ and R₉ is hydrogen. Inanother embodiment, the compounds of the invention exclude thosecompounds wherein X is a direct bond when A is formula (III).

Ether side chain component A is generally a hydrophobic moiety.Typically, a hydrophobic moiety is comprised of non-polar chemicalgroups such as hydrocarbons or hydrocarbons substituted with halogens orethers or heterocyclic groups containing nitrogen, oxygen, or sulfurring atoms. Suitable hydrocarbons are C₅-C₁₂alkyl and C₃-C₁₃-carbocyclicrings. Particularly preferred cyclic hydrocarbons include selectedaromatic groups such as phenyl, 1-naphthyl, 2-naphthyl, indenyl,acenaphthyl, and fluorenyl and are represented by formulae (III), (IV),(V), (VI), (VII), or (VIII) respectively.

A suitable “A” group within the compounds of the present invention is aphenyl ring represented by formula (III):

where R₇, R₈ and R₉ are independently selected from bromine, chlorine,fluorine, carboxy, hydrogen, hydroxy, hydroxymethyl, methanesulfonamido,nitro, sulfamyl, trifluoromethyl, C₂-C₇alkanoyloxy, C₁-C₆alkyl,C₁-C₆alkoxy, C₂-C₇alkoxycarbonyl, C₁-C₆thioalkyl, aryl and N(R₁₅,R₁₆)where R₁₅ and R₁₆ are independently selected from hydrogen, acetyl,methanesulfonyl, and C₁-C₆alkyl.

For compounds of formula (I) where X is a direct bond or CH₂, at leastone of R₇, R₈ and R₉ is preferably selected from amine (—NR₁₅R₁₆, whereR₁₅ and R₁₆ are independently hydrogen, acetyl, methanesulfonyl, andC₁-C₆alkyl), bromine, chlorine, fluorine, carboxy, hydrogen, hydroxy,hydroxymethyl, nitro, trifluoromethyl, C₂-C₇alkanoyloxy, C₁-C₆alkyl,C₁-C₆alkoxy, C₂-C₇alkylcarbonyl, C₁-C₆thioalkyl or aryl groups. Forcompounds of formula (I) when X is CH═CH, and R₃ and R₄ are hydrogen, atleast one of R₇, R₈ and R₉ is preferably a substituent other thanhydrogen. In one embodiment, the present invention provides compounds offormula (I) where A includes phenyl groups of formula (IIII) such thatat least one of R₇, R₈ and R₉ is not hydrogen, i.e., formula (III) is aphenyl group that contains at least one non-hydrogen substituent. Inanother embodiment, R₇, R₈ and R₉ are selected from amine (—NR₁₅R₁₆,where R₁₅ and R₁₆ are independently hydrogen, acetyl, methanesulfonyl,and C₁-C₆alkyl), bromine, chlorine, fluorine, carboxy, hydrogen,hydroxy, hydroxymethyl, nitro, trifluoromethyl, C₂-C₇alkanoyloxy,C₁-C₆alkyl, C₁-C₆alkoxy, C₂-C₇alkylcarbonyl and C₁-C₆thioalkyl, i.e.,none of R₇, R₈ or R₉ is aryl. In another embodiment, A does not includea phenyl ring of formula (III) when X is a direct bond.

Other suitable “A” groups in compounds of the present invention are1-naphthyl groups as represented by formula (IV):

where R₁₀ and R₁₁ are independently selected from bromine, chlorine,fluorine, carboxy, hydrogen, hydroxy, hydroxymethyl, methanesulfonamido,nitro, sulfamyl, trifluoromethyl, C₂-C₇alkanoyloxy, C₁-C₆alkyl,C₁-C₆alkoxy, C₂-C₇alkoxycarbonyl, C₁-C₆thioalkyl, and N(R₁₅,R₁₆) whereR₁₅ and R₁₆ are independently selected from hydrogen, acetyl,methanesulfonyl, and C₁-C₆alkyl.

Other suitable “A” groups in compounds of the present invention are2-naphthyl group as represented by formula (V):

where R₁₀ and R₁₁ are independently selected from bromine, chlorine,fluorine, carboxy, hydrogen, hydroxy, hydroxymethyl, methanesulfonamido,nitro, sulfamyl, trifluoromethyl, C₂-C₇alkanoyloxy, C₁-C₆alkyl,C₁-C₆alkoxy, C₂-C₇alkoxycarbonyl, C₁-C₆thioalkyl, and N(R₁₅,R₁₆) whereR₁₅ and R₁₆ are independently selected from hydrogen, acetyl,methanesulfonyl, and C₁-C₆alkyl, as defined above.

Other suitable “A” groups in compounds of the present invention arearomatic groups represented by formula (VI):

where R₁₂ is selected from bromine, chlorine, fluorine, carboxy,hydrogen, hydroxy, hydroxymethyl, methanesulfonamido, nitro, sulfamyl,trifluoromethyl, C₂-C₇alkanoyloxy, C₁-C₆alkyl, C₁-C₆alkoxy,C₂-C₇alkoxycarbonyl, C₁-C₆thioalkyl, and N(R₁₅,R₁₆) where R₁₅ and R₁₆are independently selected from hydrogen, acetyl, methanesulfonyl, andC₁-C₆alkyl; and Z is selected from CH, CH₂, O, N and S, where Z may bedirectly bonded to “X” as shown in formula (I) when Z is CH or N, or Zmay be directly bonded to R₁₇ when Z is N, and R₁₇ is selected fromhydrogen, C₁-C₆alkyl, C₃-C₈cycloalkyl, aryl and benzyl.

The aryl groups of formula (VI) are derivatives of indene, indole,benzofuran, and thianaphthene when Z is methylene, nitrogen, oxygen, andsulfur, respectively. Preferred heterocyclic groups of formula (VI)include indole where Z is NH, benzofuran where Z is O, and thianaphthenewhere Z is S. As described below, in a preferred embodiment, Z is O, Sor N—R₁₇, and in a particularly preferred embodiment Z is O or S.

Another suitable “A” group in compounds of the present invention areacenaphthyl groups as represented by formula (VII):

Still another suitable “A” group in compounds of the present inventionis the fluorenyl group represented by formula (VIII):

Preferably, ether side chain component A is an acenapthyl or fluorenylgroup only when X is a direct bond or CH₂. In further preferredembodiments, the acenaphthyl group is a 1-acenaphthyl group, and thefluorenyl group is a 9-fluorenyl group.

As mentioned above, the present invention provides aminocyclohexylethers represented by formula (I). In a preferred embodiment X is(CH₂)—Y. For these embodiments, Y is preferably a direct bond, an oxygenatom, or a sulfur atom. In a particularly preferred embodiment, Y is adirect bond or an oxygen atom. In another preferred embodiment Y is adirect bond and X is C(R₆,R₁₄), where R₆ and R₁₄ are as defined above.In another preferred embodiment, where X is C(R₁₃)═CH, R₁₃ is a hydrogenatom. For these embodiments, R₃ and R₄ are preferably independentlyattached to the cyclohexane ring at the 4- or 5-positions.

In a preferred embodiment, the invention provides compounds havingformula (IX), or a solvate or pharmaceutically acceptable salt thereof:

wherein, independently at each occurrence,

X is selected from a direct bond, —CH═CH— and —C(R₆,R₁₄)—Y—;

Y is selected from a direct bond, O and S; and

R₁, R₂, R₃, R₄, R₆, R₇, R₈, R₉, R₁₀, R₁₁, R₁₂, R₁₄, A and Z are definedas above for compounds of formula (I).

In another preferred embodiment, the invention provides a compoundhaving formula (X), or a solvate or pharmaceutically acceptable saltthereof:

wherein, independently at each occurrence,

X is selected from a direct bond, —CH═CH— and —C(R₆,R₁₄)—Y—;

Y is selected from a direct bond, O, and S;

R₁, R₂, R₆ and R₁₄ are defined as above for compounds of formula (I);

R₃ and R₄ are independently attached to the cyclohexane ring at the 4-or 5-positions, and are independently selected from hydrogen andC₁-C₆alkoxy; and

A is selected from C₅-C₁₂alkyl, C₃-C₈cycloalkyl, and any of formulae(III), (IV), (V), and (VI) as above for compounds of formula (I),wherein Z, R₇, R₈, R₉, R₁₀, R₁₁ and R₁₂ are defined as above forcompounds of formula (I).

In another preferred embodiment, the invention provides compounds havingformula (XI), or a solvate or pharmaceutically acceptable salt thereof:

wherein, independently at each occurrence,

R₁ and R₂ are defined as above for compounds of formula (I);

R₃ and R₄ are independently attached to the cyclohexane ring at the 4-or 5-positions, and are independently selected from hydrogen andmethoxy; and

A is selected from C₅-C₁₂alkyl, C₃-C₈cycloalkyl, and any of formulae(III), (IV), (V), and (VI) as above for compounds of formula (I),wherein Z, R₇, R₈, R₉, R₁₀, R₁₁ and R₁₂ are defined as above forcompounds of formula (I).

In another preferred embodiment, the invention provides compounds offormula (XII), or a solvate or pharmaceutically acceptable salt thereof:

wherein, independently at each occurrence,

R₁ and R₂ are defined as above for compounds of formula (I);

R₃ and R₄ are independently attached to the cyclohexane ring at the 4-or 5-positions, and are independently selected from hydrogen andmethoxy; and

A is selected from C₅-C₁₂alkyl, C₃-C₈cycloalkyl, and any of formulae(III), (IV), (V), and (VI) as above for compounds of formula (I),wherein Z, R₇, R₈, R₉, R₁₀, R₁₁ and R₁₂ are defined as above forcompounds of formula (I).

In another preferred embodiment, the invention provides compounds offormula (XIII), or a solvate or pharmaceutically acceptable saltthereof:

wherein, independently at each occurrence,

X is selected from —C(R₆,R₁₄)—Y— and —CH═CH—;

Y, R₁, R₂, R₆ and R₁₄ are defined as above for compounds of formula (I);

R₃ and R₄ are independently attached to the cyclohexane ring at the 4-or 5-positions, and are independently selected from hydrogen andmethoxy; and

A is selected from C₃-C₈cycloalkyl and any of formulae (III), (IV), (V),(VI), (VII) and (VIII) as above for compounds of formula (I), where R₈and R₉ are defined as above for compounds of formula (I); R₇, R₁₀, R₁₁and R₁₂ are hydrogen, and Z is selected from O, S and N—R₁₇ where R₁₇ isselected from hydrogen and methyl.

In another preferred embodiment, the invention provides compounds havingformula (XIV), or a solvate or pharmaceutically acceptable salt thereof:

wherein, independently at each occurrence,

R₁ and R₂ are defined as above for compounds of formula (I);

A is selected from any of formulae (III), (IV), (V) and (VI) as abovefor compounds of formula (I), wherein R₇, R₁₀, R₁₁, and R₁₂, arehydrogen, R₈ and R₉ are independently selected from hydrogen, hydroxy,fluorine, chlorine, bromine, methanesulfonamido, methanoyloxy,methoxycarbonyl, nitro, sulfamyl, thiomethyl, trifluoromethyl, methyl,ethyl, methoxy, ethoxy and NH₂, with the proviso that at least one of R₈and R₉ is not hydrogen; and Z is selected from O and S.

In another preferred embodiment, the invention provides compounds havingformula (XV), or a solvate or pharmaceutically acceptable salt thereof:

wherein, independently at each occurrence,

R₁ and R₂ are defined as above for compounds of formula (I); and

A is selected from any of formulae (III), (IV), (V) and (VI) as definedabove for compounds of formula (I), wherein R₇, R₁₀, R₁₁, and R₁₂, arehydrogen, R₈ and R₉ are independently selected from hydrogen, hydroxy,fluorine, chlorine, bromine, methanesulfonamido, methanoyloxy,methoxycarbonyl, nitro, sulfamyl, thiomethyl, trifluoromethyl, methyl,ethyl, methoxy, ethoxy and NH₂, with the proviso that at least one of R₈and R₉ is not hydrogen; and Z is selected from O and S.

In another preferred embodiment, the invention provides compounds havingformula (XVI), or a solvate or pharmaceutically acceptable salt thereof:

wherein, independently at each occurrence,

X is selected from a direct bond, trans-CH═CH—, —CH₂— and —CH₂—O—;

R₁ and R₂ are both methoxyethyl or, when taken together with thenitrogen atom to which they are attached, complete a ring selected frompyrrolidinyl, 2-ketopyrrolidinyl, 3-ketopyrrolidinyl,2-acetoxypyrrolidinyl, 3-acetoxypyrrolidinyl, 2-hydroxypyrrolidinyl,3-hydroxypyrrolidinyl, thiazolidinyl, piperidinyl, 2-ketopiperidinyl,3-ketopiperidinyl, 4-ketopiperidinyl, acetylpiperazinyl,1,4-dioxa-7-azaspiro[4.4]non-7-yl, hexahydroazepinyl, morpholinyl,N-methylpiperazinyl and 3-azabicyclo[3.2.2]nonanyl; and

A is selected from cyclohexyl, monochlorophenyl, 2,6-dichlorophenyl,3,4-dichlorophenyl, 2-bromophenyl, 2,4-dibromophenyl, 3-bromophenyl,4-bromophenyl, 3,4-dimethoxyphenyl, 1-naphthyl, 2-naphthyl,3-benzo[b]thiophenyl, 4-benzo[b]thiophenyl, (2-trifluoromethyl)phenyl,2,4-di(trifluoromethyl)phenyl, and (4-trifluoromethyl)phenyl.

In another preferred embodiment, the invention provides compounds havingformula (XVII), or a solvate or pharmaceutically acceptable saltthereof:

wherein, independently at each occurrence,

n is selected from 1, 2 and 3;

R₁₈ is either hydrogen or methyl and is independently attached to thecyclohexane ring shown in formula (XVII) at one of the 3-, 4-, 5- or6-positions;

R₁₉ is selected from a group consisting of bromine, chlorine, fluorineand hydrogen; and

R₂₀ is selected from a group consisting of bromine, chlorine andfluorine;

including isolated enantiomeric, diastereomeric and geometric isomersthereof, and mixtures thereof.

In another preferred embodiment, the invention provides compounds havinga trans configuration of formula (XVII) as represented by formula(XVIII), or a solvate or pharmaceutically acceptable salt thereof:

wherein, independently at each occurrence,

n is selected from 1, 2 and 3;

R₁₈ is either hydrogen or methyl and is independently attached to thecyclohexane ring shown in formula (XVII) at one of the 3-, 4-, 5- or6-positions;

R₁₉ is selected from a group consisting of bromine, chlorine, fluorineand hydrogen; and

R₂₀ is selected from a group consisting of bromine, chlorine andfluorine;

including isolated enantiomeric, diastereomeric and geometric isomersthereof, and mixtures thereof.

In yet another preferred embodiment, the invention provides compoundshaving formula (IXX); or a solvate or pharmaceutically acceptable saltthereof:

wherein, independently at each occurrence,

n is selected from 1, 2 and 3;

R₁₈ is either hydrogen or methyl and is independently attached to thecyclohexane ring shown in formula (XVII) at one of the 3-, 4-, 5- or6-positions;

R₁₉ is selected from a group consisting of bromine, chlorine, fluorineand hydrogen; and

R₂₀ is selected from a group consisting of bromine, chlorine andfluorine;

including isolated enantiomeric, diastereomeric and geometric isomersthereof, and mixtures thereof.

The following are further preferred compounds of the present invention,including isolated enantiomeric and diastereomeric isomers thereof, andmixtures thereof; and pharmaceutically acceptable salts thereof:

Outline of Method of Preparation of Compounds of the Invention

The aminocyclohexyl ether compounds of the present invention containamino and ether sidechains disposed in a 1,2 arrangement on acyclohexane ring. Accordingly, the amino and ether sidechains may bedisposed in either a cis or trans relationship, relative to one anotherand the plane of the cyclohexane ring. The present invention providessynthetic methodology whereby cis or trans compounds may be prepared.

Trans compounds of the present invention may be prepared in analogy withknown synthetic methodology (see, e.g., Shanklin, Jr. et al., U.S. Pat.No. 5,130,309). FIG. 1 outlines the preparation of a trans compound ofthe invention, where this preparation is more fully described inExample 1. As outlined in FIG. 1, the preparation of a trans compound ofthe invention may be achieved by following a four step procedure.

In a first step (denoted “i)” in FIG. 1), cyclohexene epoxide undergoesa ring-opening reaction with an amine. See, e.g., Szmuszkovicz, U.S.Pat. No. 4,145,435. While the reaction can occur at room temperature,typically elevated temperature is preferred in order to drive thereaction to completion in a commercially desirable length of time. Thereaction is typically conducted in a solvent, such as water, and thereflux temperature of the solvent provides a suitable temperature. Equalmolar amounts of the amine and cyclohexene epoxide typically providesatisfactory results. In any event, the amine nitrogen reacts with theepoxide group to form a 1-hydroxy 2-amino cyclohexane, where the hydroxyand amine groups are typically disposed in a trans relationship. A widevariety of amine compounds and substituted cyclohexene oxides may beemployed in this general reaction, and FIG. 1 illustrates this reactionin the instance where the amine is morpholine and the cyclohexene oxideis unsubstituted. For other amines or substituted cyclohexene epoxidesthat may contain other reactive functional groups, appropriateprotection groups are introduced prior to step i) being carried out.Suitable protecting groups are set forth in, for example, Greene,“Protective Groups in Organic Chemistry”, John Wiley & Sons, New YorkN.Y. (1991).

In a second step (denoted “ii)” in FIG. 1) the hydroxy group that wasderived from the epoxide, is converted into an activated form. An“activated form” as used herein means that the hydroxy group isconverted into a good leaving group. The leaving group illustrated inFIG. 1 is a mesylate group, and that is a preferred leaving group.However, the hydroxy group could be converted into other leaving groupsaccording to procedures well known in the art. In a typical reaction,the aminocyclohexanol compound is treated with methanesulfonyl chloridein the presence of a base, such as triethylamine as shown in FIG. 1. Thereaction is satisfactorily conducted at about 0° C. An excess of themethanesulfonyl chloride, relative to the aminocyclohexanol, istypically preferred in order to maximally convert the more valuableaminocyclohexanol into the activated form. For some otheraminocyclohexanol compounds, it may be necessary to introduceappropriate protection groups prior to step ii) being performed.Suitable protecting groups are set forth in, for example, Greene,“Protective Groups in Organic Chemistry”, John Wiley & Sons, New YorkN.Y. (1991).

In a third step (denoted “iii)” in FIG. 1) an alcohol is reacted with astrong base to provide an alkoxide salt. Conversion of an alcohol to analkoxide (also known as an alcoholate) using strong base is a generalreaction, and will work with a wide variety of hydroxy-containingcompounds. In some instances, the alcohol compound may have otherreactive functional groups that are desirably protected prior to contactof the alcohol with strong base. Suitable protecting groups are setforth in, for example, Greene, “Protective Groups in Organic Chemistry”,John Wiley & Sons, New York N.Y. (1991). Such alcohols are eithercommercially available or may be obtained by procedures described in theart or adapted therefrom, where suitable procedures may be identifiedthrough the Chemical Abstracts and Indices therefor, as developed andpublished by the American Chemical Society.

In a fourth step (denoted “iv)” in FIG. 1), the alcoholate of step“iii)” is reacted with the activated aminocyclohexanol of step “ii)”.Thus, generally stated, compounds of the present invention may beprepared by reacting an activated form of the appropriate1,2-aminocyclohexanol (1 mol) with an alcoholate (1.25 mol) prepared bytreatment of the selected alcohol (1.25 mol) with, for example, sodiumhydride (1.3 mol). The 1,2-aminocyclohexanol (1 mol) can be activated byforming the corresponding mesylate, in the presence of methanesulfonylchloride (1.25 mol) and triethylamine (1.5 mol). The mesylate is addedquickly to the alcoholate, in a suitable solvent such asdimethylformamide. The reaction temperature is monitored carefully inorder to avoid undesired side-reactions such as β-elimination. Ingeneral, a reaction temperature of 80-90° C. for 2 hours is typicallysuitable to form compounds of the invention. When the reaction hasproceeded to substantial completion, the desired product is recoveredfrom the reaction mixture by conventional organic chemistry techniques,and is purified generally by column chromatography followed byrecrystallisation. Protective groups may be removed at the appropriatestage of the reaction sequence. Suitable methods are set forth in, forexample, Greene, “Protective Groups in Organic Chemistry”, John Wiley &Sons, New York N.Y. (1991).

The reaction sequence described above (and shown in FIG. 1) generatesthe aminocyclohexyl ether as the free base. The pure enantiomeric formscan be obtained by preparative chiral HPLC. The free base may beconverted, if desired, to the monohydrochloride salt by knownmethodologies, and subsequently, if desired, to other acid additionsalts by reaction with inorganic or organic salts. Acid addition saltscan also be prepared metathetically by reacting one acid addition saltwith an acid which is stronger than that of the anion of the initialsalt.

Cis or trans compounds of the invention may be prepared according to thechemistry outlined in FIG. 2. As shown in FIG. 2,1,2-aminocyclohexanones may be prepared by Swern oxidation of thecorresponding trans-1,2-aminocyclohexanol compounds (which may beprepared as described above) using oxalyl chloride/dimethyl sulfoxide(see, e.g., Synthesis 1980, 165). Subsequent reduction of theaminocyclohexanone with lithium aluminum hydride or sodium borohydrideprovides a mixture of cis- and trans-aminocyclohexanols. The mixture ofaminoalcohols may be esterified with an appropriate carboxylic acid byazeotropic distillation in toluene in the presence of a catalytic amountof p-toluenesulfonic acid, to provide a diastereomeric mixture of cis-and trans-esters. The mixture of diastereomeric esters can be separatedby preparative chromatography by one of ordinary skill in the art. Theracemic cis- or trans ester preparation could then be reduced withsodium borohydride in the presence of Lewis acid to the correspondingracemic cis- or trans-ether (see, e.g., J. Org. Chem. 25, 875, 1960 andTetrahedron 18, 953, 1962). The racemic cis-ether can be resolved bypreparative chiral HPLC as discussed above for the trans-compound.

Alternatively, cis and trans compounds of the invention may be preparedaccording to the chemistry outlined in FIG. 3. As shown in FIG. 3,cyclohexene oxide can react with an alcohol (ROH) in the present ofMg(ClO₄)₂ (see, e.g., M. Chini et al., Synlett, 673-676, 1992) toprovide 1,2-hydroxycyclohexyl ethers. Oxidation with pyridiniumdichromate (see, e.g., R. Oshima et al., J. Org. Chem., 50, 2613-2621,1985) yielded the corresponding 1,2-alkoxycyclohexanone. Subsequentreductive amination (R. F. Borch et al., J. Am. Chem. Soc., 93(12),2897-2904, 1971) provides a mixture of cis- and trans-aminocyclohexylethers. The mixture of diastereomeric ethers can be separated bychromatography by one of ordinary skill in the art. The racemic cis- ortrans-ether so prepared could then be resolved by classicalrecrystallization methods well known in the art or by preparative chiralHPLC to provide the individual enantiomer: trans-(1R,2R), trans-(1S,2S),cis-(1R,2S) or cis-(1S,2R) aminoethers.

The synthetic procedures described herein, especially when taken withthe general knowledge in the art, provide sufficient guidance to thoseof ordinary skill in the art to perform the synthesis, isolation, andpurification of the compounds of the present invention.

Compositions and Modes of Administration

In another embodiment, the present invention provides compositions whichinclude a cyclohexylamine compound as described above in admixture orotherwise in association with one or more inert carriers, excipients anddiluents, as well as optional ingredients if desired. These compositionsare useful as, for example, assay standards, convenient means of makingbulk shipments, or pharmaceutical compositions. An assayable amount of acompound of the invention is an amount which is readily measurable bystandard assay procedures and techniques as are well known andappreciated by those skilled in the art. Assayable amounts of a compoundof the invention will generally vary from about 0.001 wt % to about 75wt % of the entire weight of the composition. Inert carriers include anymaterial which does not degrade or otherwise covalently react with acompound of the invention. Examples of suitable inert carriers arewater; aqueous buffers, such as those which are generally useful in HighPerformance Liquid Chromatography (HPLC) analysis; organic solvents suchas acetonitrile, ethyl acetate, hexane and the like (which are suitablefor use in in vitro diagnostics or assays, but typically are notsuitable for administration to a warm-blooded animal); andpharmaceutically acceptable carriers, such as physiological saline.

Thus, the present invention provides a pharmaceutical or veterinarycomposition (hereinafter, simply referred to as a pharmaceuticalcomposition) containing a cyclohexylamine compound as described above,in admixture with a pharmaceutically acceptable carrier, excipient ordiluent. The invention further provides a pharmaceutical compositioncontaining an effective amount of a cyclohexylamine compound asdescribed above, in association with a pharmaceutically acceptablecarrier.

The pharmaceutical compositions of the present invention may be in anyform which allows for the composition to be administered to a patient.For example, the composition may be in the form of a solid, liquid orgas (aerosol). Typical routes of administration include, withoutlimitation, oral, topical, parenteral, sublingual, rectal, vaginal, andintranasal. The term parenteral as used herein includes subcutaneousinjections, intravenous, intramuscular, epidural, intrasternal injectionor infusion techniques. Pharmaceutical composition of the invention areformulated so as to allow the active ingredients contained therein to bebioavailable upon administration of the composition to a patient.Compositions that will be administered to a patient take the form of oneor more dosage units, where for example, a tablet, capsule or cachet maybe a single dosage unit, and a container of cyclohexylamine compound inaerosol form may hold a plurality of dosage units.

Materials used in preparing the pharmaceutical compositions should bepharmaceutically pure and non-toxic in the amounts used. The inventivecompositions may include one or more compounds (active ingredients)known for a particularly desirable effect. For instance, epinephrine maybe combined with an aminocyclohexyl ether compound of the invention, toprovide a composition useful to induce local anesthesia. It will beevident to those of ordinary skill in the art that the optimal dosage ofthe active ingredient(s) in the pharmaceutical composition will dependon a variety of factors. Relevant factors include, without limitation,the type of subject (e.g., human), the particular form of the activeingredient, the manner of administration and the composition employed.

In general, the pharmaceutical composition includes a cyclohexylaminecompound as described herein, in admixture with one or more carriers.The carrier(s) may be particulate, so that the compositions are, forexample, in tablet or powder form. The carrier(s) may be liquid, withthe compositions being, for example, an oral syrup or injectable liquid.In addition, the carrier(s) may be gaseous, so as to provide an aerosolcomposition useful in, e.g., inhalatory administration.

When intended for oral administration, the composition is preferably ineither solid or liquid form, where semi-solid, semi-liquid, suspensionand gel forms are included within the forms considered herein as eithersolid or liquid.

As a solid composition for oral administration, the composition may beformulated into a powder, granule, compressed tablet, pill, capsule,cachet, chewing gum, wafer, lozenges, or the like form. Such a solidcomposition will typically contain one or more inert diluents or ediblecarriers. In addition, one or more of the following adjuvants may bepresent: binders such as syrups, acacia, sorbitol, polyvinylpyrrolidone,carboxymethylcellulose, ethyl cellulose, microcrystalline cellulose, gumtragacanth or gelatin, and mixtures thereof, excipients such as starch,lactose or dextrins, disintegrating agents such as alginic acid, sodiumalginate, Primogel, corn starch and the like; lubricants such asmagnesium stearate or Sterotex; fillers such as lactose, mannitols,starch, calcium phosphate, sorbitol, methylcellulose, and mixturesthereof, lubricants such as magnesium stearate, high molecular weightpolymers such as polyethylene glycol, high molecular weight fatty acidssuch as stearic acid, silica, wetting agents such as sodium laurylsulfate, glidants such as colloidal silicon dioxide; sweetening agentssuch as sucrose or saccharin, a flavoring agent such as peppermint,methyl salicylate or orange flavoring, and a coloring agent.

When the composition is in the form of a capsule, e.g., a gelatincapsule, it may contain, in addition to materials of the above type, aliquid carrier such as polyethylene glycol or a fatty oil.

The composition may be in the form of a liquid, e.g., an elixir, syrup,solution, aqueous or oily emulsion or suspension, or even dry powderswhich may be reconstituted with water and/or other liquid media prior touse. The liquid may be for oral administration or for delivery byinjection, as two examples. When intended for oral administration,preferred compositions contain, in addition to the present compounds,one or more of a sweetening agent, thickening agent, preservative (e.g.,alkyl p-hydroxybenzoate), dye/colorant and flavor enhancer (flavorant).In a composition intended to be administered by injection, one or moreof a surfactant, preservative (e.g., alkyl p-hydroxybenzoate), wettingagent, dispersing agent, suspending agent (e.g., sorbitol, glucose, orother sugar syrups), buffer, stabilizer and isotonic agent may beincluded. The emulsifying agent may be selected from lecithin orsorbitol monooleate.

The liquid pharmaceutical compositions of the invention, whether they besolutions, suspensions or other like form, may include one or more ofthe following adjuvants: sterile diluents such as water for injection,saline solution, preferably physiological saline, Ringer's solution,isotonic sodium chloride, fixed oils such as synthetic mono ordigylcerides which may serve as the solvent or suspending medium,polyethylene glycols, glycerin, propylene glycol or other solvents;antibacterial agents such as benzyl alcohol or methyl paraben;antioxidants such as ascorbic acid or sodium bisulfite; chelating agentssuch as ethylenediaminetetraacetic acid; buffers such as acetates,citrates or phosphates and agents for the adjustment of tonicity such assodium chloride or dextrose. The parenteral preparation can be enclosedin ampoules, disposable syringes or multiple dose vials made of glass orplastic. Physiological saline is a preferred adjuvant. An injectablepharmaceutical composition is preferably sterile.

A liquid compositions intended for either parenteral or oraladministration should contain an amount of the inventive compound suchthat a suitable dosage will be obtained. Typically, this amount is atleast 0.01% of a compound of the invention in the composition. Whenintended for oral administration, this amount may be varied to bebetween 0.1 and about 70% of the weight of the composition. Preferredoral compositions contain between about 4% and about 50% of the activecyclohexylamine compound. Preferred compositions and preparationsaccording to the present invention are prepared so that a parenteraldosage unit contains between 0.01 to 10% by weight of active compound.

The pharmaceutical composition may be intended for topicaladministration, in which case the carrier may suitably comprise asolution, emulsion, ointment, cream or gel base. The base, for example,may comprise one or more of the following: petrolatum, lanolin,polyethylene glycols, bee wax, mineral oil, diluents such as water andalcohol, and emulsifiers and stabilizers. Thickening agents may bepresent in a pharmaceutical composition for topical administration. Ifintended for transdermal administration, the composition may include atransdermal patch or iontophoresis device. Topical formulations maycontain a concentration of the inventive compound of from about 0.1 toabout 25% w/v (weight per unit volume).

The composition may be intended for rectal administration, in the form,e.g., of a suppository which will melt in the rectum and release thedrug. The composition for rectal administration may contain anoleaginous base as a suitable nonirritating excipient. Such basesinclude, without limitation, lanolin, cocoa butter and polyethyleneglycol. Low-melting waxes are preferred for the preparation of asuppository, where mixtures of fatty acid glycerides and/or cocoa butterare suitable waxes. The waxes may be melted, and the cyclohexylaminecompound is dispersed homogeneously therein by stirring. The moltenhomogeneous mixture is then poured into convenient sized molds, allowedto cool and thereby solidify.

The composition may include various materials which modify the physicalform of a solid or liquid dosage unit. For example, the composition mayinclude materials that form a coating shell around the activeingredients. The materials which form the coating shell are typicallyinert, and may be selected from, for example, sugar, shellac, and otherenteric coating agents. Alternatively, the active ingredients may beencased in a gelatin capsule or cachet.

The composition in solid or liquid form may include an agent which bindsto the cyclohexylamine compound and thereby assists in the delivery ofthe active components. Suitable agents which may act in this capacityinclude a monoclonal or polyclonal antibody, a protein or a liposome.

The pharmaceutical composition of the present invention may consist ofgaseous dosage units, e.g., it may be in the form of an aerosol. Theterm aerosol is used to denote a variety of systems ranging from thoseof colloidal nature to systems consisting of pressurized packages.Delivery may be by a liquefied or compressed gas or by a suitable pumpsystem which dispenses the active ingredients. Aerosols of compounds ofthe invention may be delivered in single phase, bi-phasic, or tri-phasicsystems in order to deliver the active ingredient(s). Delivery of theaerosol includes the necessary container, activators, valves,subcontainers, and the like, which together may form a kit. Preferredaerosols may be determined by one skilled in the art, without undueexperimentation.

Whether in solid, liquid or gaseous form, the pharmaceutical compositionof the present invention may contain one or more known pharmacologicalagents used in methods for either modulating ion channel activity in awarm-blooded animal or for modulating ion channel activity in vitro, orused in the treatment of arrhythmia, diseases of the central nervoussystem, convulsion, epileptic spasms, depression, anxiety,schizophrenia, Parkinson's disease, respiratory disorders, cysticfibrosis, asthma, cough, inflammation, arthritis, allergies,gastrointestinal disorders, urinary incontinence, irritable bowelsyndrome, cardiovascular diseases, cerebral or myocardial ischemias,hypertension, long-QT syndrome, stroke, migraine, ophthalmic diseases,diabetes mellitus, myopathies, Becker's myotonia, myasthenia gravis,paramyotonia congentia, malignant hyperthermia, hyperkalemic periodicparalysis, Thomsen's myotonia, autoimmune disorders, graft rejection inorgan transplantation or bone marrow transplantation, heart failure,hypotension, Alzheimer's disease and other metal disorders, andalopecia. Other agents known to cause libido enhancement, localanalgesia or anesthesia may be combined with compounds of the presentinvention.

The pharmaceutical compositions may be prepared by methodology wellknown in the pharmaceutical art. The aminocyclohexyl compounds of theinvention may be in the form of a solvate in a pharmaceuticallyacceptable solvent such as water or physiological saline. Alternatively,the compounds may be in the form of the free base or in the form of apharmaceutically acceptable salt such as the hydrochloride, sulfate,phosphate, citrate, fumarate, methanesulfonate, acetate, tartrate,maleate, lactate, mandelate, salicylate, succinate and other salts knownin the art. The appropriate salt would be chosen to enhancebioavailability or stability of the compound for the appropriate mode ofemployment (e.g., oral or parenteral routes of administration).

A composition intended to be administered by injection can be preparedby combining the cyclohexylamine compound with water, and preferablybuffering agents, so as to form a solution. The water is preferablysterile pyrogen-free water. A surfactant may be added to facilitate theformation of a homogeneous solution or suspension. Surfactants arecompounds that non-covalently interact with the cyclohexylamine compoundso as to facilitate dissolution or homogeneous suspension of thecyclohexylamine compound in the aqueous delivery system. Surfactants aredesirably present in aqueous compositions of the invention because thecyclohexylamine compounds of the present invention are typicallyhydrophobic. Other carriers for injection include, without limitation,sterile peroxide-free ethyl oleate, dehydrated alcohols, propyleneglycol, as well as mixtures thereof.

Suitable pharmaceutical adjuvants for the injecting solutions includestabilizing agents, solubilizing agents, buffers, and viscosityregulators. Examples of these adjuvants include ethanol,ethylenediaminetetraacetic acid (EDTA), tartrate buffers, citratebuffers, and high molecular weight polyethylene oxide viscosityregulators. These pharmaceutical formulations may be injectedintramuscularly, epidurally, intraperitoneally, or intravenously.

Pharmacological Testing

As noted above, the present invention provides for utilizing thecompounds described above in in vitro and in vivo methods. In oneembodiment, ion channels, such as cardiac sodium channels, are blockedin vitro or in vivo.

Ion channels are ubiquitous membrane proteins in the cells ofwarm-blooded animals such as mammals. Their critical physiological rolesinclude control of the electrical potential across the membrane,mediation of ionic and fluid balance, facilitation of neuromuscular andneuronal transmission, rapid transmembrane signal transduction, andregulation of secretion and contractility.

Accordingly, compounds that are capable of modulating the activity orfunction of the appropriate ion channels will be useful in treating orpreventing a variety of diseases or disorders caused by defective orinadequate function of the ion channels. The compounds of the inventionare found to have significant activity in modulating ion channelactivity both in vivo and in vitro.

Thus, the present invention provides for methods of treating a diseaseor condition in a warm-blooded animal suffering from or having thedisease or condition, and/or preventing a disease or condition fromarising in a warm-blooded animal, wherein a therapeutically effectiveamount of a compound of formula (I), or a composition containing acompound of formula (I) is administered to a warm-blooded animal in needthereof. The diseases and conditions to which the compounds,compositions and methods of the present invention may be applied asfollows: arrhythmia, diseases of the central nervous system, convulsion,epileptic spasms, depression, anxiety, schizophrenia, Parkinson'sdisease, respiratory disorders, cystic fibrosis, asthma, cough,inflammation, arthritis, allergies, gastrointestinal disorders, urinaryincontinence, irritable bowel syndrome, cardiovascular diseases,cerebral or myocardial ischemias, hypertension, long-QT syndrome,stroke, migraine, ophthalmic diseases, diabetes mellitus, myopathies,Becker's myotonia, myasthenia gravis, paramyotonia congentia, malignanthyperthermia, hyperkalemic periodic paralysis, Thomsen's myotonia,autoimmune disorders, graft rejection in organ transplantation or bonemarrow transplantation, heart failure, hypotension, Alzheimer's diseaseor other mental disorder, and alopecia.

Furthermore, the present invention provides a method for producing localanalgesia or anesthesia in a warm-blooded animal which includesadministering to a warm-blooded animal in need thereof an effectiveamount of a compound of formula (I) or a pharmaceutical compositioncontaining a compound of formula (I). These methods may be used torelieve or forestall the sensation of pain in a warm-blooded animal.

Furthermore, the present invention provides a method wherein apreparation that contains ion channels is contacted with, or awarm-blooded animal (e.g., a mammal, such as a human) is administered aneffective amount of an aminocyclohexyl ether compound of the invention.Suitable preparations containing cardiac sodium channels include cellsisolated from cardiac tissue as well as cultured cell lines. The step ofcontacting includes, for example, incubation of ion channels with acompound under conditions and for a time sufficient to permit modulationof the activity of the channels by the compound.

In another embodiment, the compounds described above are provided fortreating arrhythmia. As used herein, “treating arrhythmia” refers toboth therapy for arrhythmia and for the prevention of arrhythmiasoccurring in a heart that is susceptible to arrhythmia. An effectiveamount of a composition of the present invention is used to treatarrhythmia in a warm-blooded animal, such as a human. Methods ofadministering effective amounts of antiarrhythmic agents are well knownin the art and include the administration of an oral or parenteraldosage form. Such dosage forms include, but are not limited to,parenteral dosage form. Such dosage forms include, but are not limitedto, parenteral solutions, tablets, capsules, sustained release implants,and transdermal delivery systems. Generally, oral or intravenousadministration is preferred. The dosage amount and frequency areselected to create an effective level of the agent without harmfuleffects. It will generally range from a dosage of from about 0.1 toabout 100 mg/kg/day, and typically from about 0.1 to 10 mg/kg whereadministered orally or intravenously for antiarrhythmic effect.

Administration of compositions of the present invention may be carriedout in combination with the administration of other agents. For example,it may be desired to administer an opioid antagonist, such as naloxone,if a compound exhibits opioid activity where such activity may not bedesired. The naloxone may antagonize opioid activity of the administeredcompound without adverse interference with the antiarrhythmic activity.As another example, an aminocyclohexyl ether compound of the inventionmay be co-administered with epinephrine in order to include localanesthesia.

In order to assess whether a compound has a desired pharmacologicalactivity with the present invention, it is subjected to a series oftests. The precise test to employ will depend on the physiologicalresponse of interest. The published literature contains numerousprotocols for testing the efficacy of a potential therapeutic agent, andthese protocols may be employed with the present compounds andcompositions.

For example, in connection with treatment or prevention of arrhythmia, aseries of four tests may be conducted. In the first of these tests, acompound of the present invention is given as increasing (doubling witheach dose) intravenous boluses every 8 minutes to a pentobarbitalanesthetized rat. The effects of the compound on blood pressure, heartrate and the ECG are measured 30 seconds, 1, 2, 4 and 8 minutes aftereach dose. Increasing doses are given until the animal dies. The causeof death is identified as being of either respiratory or cardiac origin.This test gives an indication as to whether the compound is modulatingthe activity of sodium channels and/or potassium channels, and inaddition gives information about acute toxicity. The indices of sodiumchannel blockade are increasing P—R interval and QRS widening of theECG. Potassium channel blockade results in Q-T interval prolongation ofthe ECG.

A second test involves administration of a compound as an infusion topentobarbital anesthetized rats in which the left ventricle is subjectedto electrical square wave stimulation performed according to a presetprotocol described in further detail below. This protocol includes thedetermination of thresholds for induction of extrasystoles andventricular fibrillation. In addition, effects on electricalrefractoriness are assessed by a single extra beat technique. Inaddition effects on blood pressure, heart rate and the ECG are recorded.In this test, sodium channel blockers produce the ECG changes expectedfrom the first test. In addition, sodium channel blockers also raise thethresholds for induction of extrasystoles and ventricular fibrillation.Potassium channel blockade is revealed by increasing refractoriness andwidening of the Q-T intervals of the ECG.

A third test involves exposing isolated rat hearts to increasingconcentrations of a compound. Ventricular pressures, heart rate,conduction velocity and ECG are recorded in the isolated heart in thepresence of varying concentrations of the compound. The test providesevidence for direct toxic effects on the myocardium. Additionally,selectivity, potency and efficacy of action of a compound can beascertained under conditions simulating ischemia. Concentrations foundto be effective in this test are expected to be efficacious in theelectrophysiological studies.

A fourth test is estimation of the antiarrhythmic activity of a compoundagainst the arrhythmias induced by coronary artery occlusion inanaesthetized rats. It is expected that a good antiarrhythmic compoundwill have antiarrhythmic activity at doses which have minimal effects oneither the ECG, blood pressure or heart rate under normal conditions.

All of the foregoing tests are performed using rat tissue. In order toensure that a compound is not having effects which are only specific torat tissue, further experiments are performed in dogs and primates. Inorder to assess possible sodium channel and potassium channel blockingaction in vivo in dogs, a compound is tested for effects on the ECG,ventricular epicardial conduction velocity and responses to electricalstimulation. An anesthetized dog is subjected to an open chest procedureto expose the left ventricular epicardium. After the pericardium isremoved from the heart a recording/stimulation electrode is sewn ontothe epicardial surface of the left ventricle. Using this array, andsuitable stimulation protocols, conduction velocity across theepicardium as well as responsiveness to electrical stimulation can beassessed. This information coupled with measurements of the ECG allowsone to assess whether sodium and/or potassium channel blockade occurs.As in the first test in rats, a compound is given as a series ofincreasing bolus doses. At the same time possible toxic effects of acompound on the dog's cardiovascular system is assessed.

The effects of a compound on the ECG and responses to electricalstimulation are also assessed in intact, halothane anesthetized baboons(Papio anubis). In this preparation, a blood pressure cannula and ECGelectrodes are suitably placed in an anesthetized baboon. In addition, astimulating electrode is placed into the right ventricle, together witha monophasic action potential electrode. As in the tests describedabove, ECG and electrical stimulation response to a compound reveal thepossible presence of sodium and/or potassium channel blockade. Themonophasic action potential also reveals whether a compound widens theaction potential, an action expected of a potassium channel blocker.

In addition to the tests described above and in Examples 28-31, thepharmacological activity related to atrial arrhythmia (e.g. atrialfibrillation and atrial flutter) of the compounds of the presentinvention may be evaluated by other in vivo animal models established inthe literature. Two such models are described below in Example 32 andExample 33.

As another example, in connection with the mitigation or prevention ofthe sensation of pain, the following test may be performed. To determinethe effects of a compound of the present invention on an animal'sresponse to a sharp pain sensation, the effects of a slight prick from a7.5 g weighted syringe fitted with a 23 G needle as applied to theshaved back of a guinea pig (Cavia porcellus) is assessed followingsubcutaneous administration of sufficient (50 μl, 10 mg/ml) solution insaline to raise a visible bleb on the skin. Each test was done on thecentral area of the bleb and also on its periphery to check fordiffusion of the test solution from the point of administration. If thetest animal produces a flinch in response to the stimulus, thisdemonstrates the absence of blockade of pain sensation. Testing wascarried out at intervals for up to 4 hours post administration. Thesites of bleb formation were examined after 24 hours and showed no skinabnormalities consequent to local administration of test substances orof saline, the vehicle used for preparation of the test solutions.

Other Compositions

The present invention also provides kits that contain a pharmaceuticalcomposition which includes one or more compounds of the above formulae.The kit also includes instructions for the use of the pharmaceuticalcomposition for modulating the activity of ion channels, for thetreatment of arrhythmia or for the production of local analgesia and/oranesthesia, and for the other utilities disclosed herein. Preferably, acommercial package will contain one or more unit doses of thepharmaceutical composition. For example, such a unit dose may be anamount sufficient for the preparation of an intravenous injection. Itwill be evident to those of ordinary skill in the art that compoundswhich are light and/or air sensitive may require special packagingand/or formulation. For example, packaging may be used which is opaqueto light, and/or sealed from contact with ambient air, and/or formulatedwith suitable coatings or excipients.

The following examples are offered by way of illustration and not by wayof limitation. In the Examples, and unless otherwise specified, startingmaterials were obtained from well-known commercial supply houses, e.g.,Aldrich Chemical Company (Milwaukee, Wis.), and were of standard gradeand purity. “Ether” and “ethyl ether” each refers to diethyl ether; “h.”refers to hours; “min.” refers to minutes; “GC” refers to gaschromatography; “v/v” refers to volume per volume; and ratios are weightratios unless otherwise indicated.

EXAMPLES Example 1(±)-Trans-[2-(4-Morpholinyl)-1-(2-Naphthenethoxy)]CyclohexaneMonohydrochloride Compound #1

(i) Morpholine (5 mL, 57 mmol), cyclohexene oxide (5.8 mL, 57 mmol) andwater (3 mL) were refluxed for 1.5 h. GC analysis showed the reaction tobe complete. The cooled mixture was partitioned between saturated NaOHsolution (50 mL) and ether (75 mL). The aqueous layer was backwashedwith ether (30 mL) and the combined ether layers were dried over sodiumsulfate. The ether was removed in vacuo to leave a yellow oil (9.83 g).The crude product, (±)-trans-[2-(4-morpholinyl)]cyclohexanol, waspurified by vacuum distillation (b.p. 75-80° C. at full vacuum) to givea clear liquid (8.7 g). Yield 82.5%.

(ii) To a chilled (0° C.) solution of(±)-trans-[2-(4-morpholinyl)]cyclohexanol (6.0 g, 32.4 mmol) andtriethylamine (6.8 mL, 48 mmol) in dichloromethane (100 mL) was addedvia cannula a solution of methanesulfonyl chloride (3.10 mL, 40 mmol) indichloromethane (50 mL). The addition was completed in 10 min., thereaction mixture was stirred for another hour at 0° C. and then at roomtemperature for 4 hours. The dichloromethane mixture was washed withwater (2×50 mL) and the combined aqueous washings back extracted withdichloromethane (50 mL). The combined organic layers were dried oversodium sulfate and concentrated in vacuo to provide 8.5 g (100% yield)of the crude mesylate.

(iii) To sodium hydride, 80% oil dispersion previously washed withhexanes (3×20 mL), (1.24 g, 51.6 mmol) in dry dimethylformamide (50 mL)was added via cannula a solution of 2-naphthenethanol (6.8 g, 40 mmol)in dry dimethylformamide (50 mL). Addition was followed by gas evolutionand, as the reaction mixture was stirred at room temperature, it beganto gel. The mesylate as prepared in (ii) above was dissolved indimethylformamide (50 mL) and the resulting solution was added quicklyvia cannula to the slurry of alcoholate. The reaction mixture was heatedto 80° C. and then the temperature reduced to 40° C. The resultingyellow solution was poured into ice-water (1500 mL) and extracted withethyl acetate (3×300 mL). The combined organic extracts were backwashedwith a saturated aqueous solution of sodium chloride (500 mL) and driedover sodium sulfate. Evaporation of the solvent in vacuo provided 13.4 gof an amber oil which was dissolved in water (150 mL) and the pH of thesolution was adjusted to pH 2 with aqueous 1M HCl. The acidic aqueoussolution was extracted with ethyl ether (2×100 mL) and then basified topH 10 with 50% sodium hydroxide aqueous solution. The basic aqueoussolution was extracted with ethyl ether (2×100 mL), the combined organiclayers were dried over sodium sulfate and concentrated in vacuo to leave7.16 g of the crude free aminoether. The crude product was purified bychromatography on silica gel 60 (70-230 mesh) with a mixture of ethylacetate-chloroform (1:1, v/v) as eluent to yield 4.37 g of the pure freebase. The product was dissolved in ethyl ether (80 mL) and converted tothe monohydrochloride salt by adding saturated solution of HCl in ethylether (80 mL). An oil came out of the solution, the solvent wasevaporated in vacuo and the residue dissolved in the minimum amount ofwarm ethyl alcohol, addition of a large volume of ethyl ether triggeredcrystallization. The crystals were collected to afford 3.83 g (31%yield) of the title compound, m.p. 158-160° C., having the elementalanalysis indicated in Table 1.

Example 2 (±)-Trans-[2-(4-Morpholinyl)-1-(1-Naphthenethoxy)]CyclohexaneMonohydrochloride Compound #2

(i) The starting trans-aminocyclohexanol is prepared according toexample 1.

(ii) To a chilled (0° C.) solution of(±)-trans-[2-(4-morpholinyl)]cyclohexanol (6.0 g, 32 mmol) andtriethylamine (6.8 mL, 48 mmol) in dichloromethane (100 mL) was addedvia cannula a solution of methanesulfonyl chloride (3.10 mL, 40 mmol) indichloromethane (50 mL). The addition was completed in 10 min., thereaction mixture was stirred for another hour at 0° C. and then at roomtemperature for 4 hours. The dichloromethane mixture was washed withwater (2×50 mL) and the combined aqueous washings back extracted withdichloromethane (50 mL). The combined organic layers were dried oversodium sulfate and concentrated in vacuo to provide 9.0 g of the crudemesylate.

(iii) To sodium hydride, 80% oil dispersion, previously washed withhexanes (3×20 mL) (1.30 g, 51.6 mmol), in dry dimethylformamide (50 mL)was added via cannula a solution of 1-naphthenethanol (6.8 g, 40 mmol)in dry dimethylformamide (50 mL). Addition was followed by evolution ofgas and the reaction mixture was stirred at room temperature for 4hours. The mesylate as prepared in (ii) above was dissolved in drydimethylformamide (50 mL) and the resulting solution was added quickly(3 min.) via cannula to the slurry of alcoholate. The reaction mixturewas heated to 80° C. for 3 hours, then the temperature was reduced to35° C. for overnight stirring. The reaction mixture was poured intoice-water (1500 mL) and extracted with ethyl acetate (3×300 mL). Thecombined organic extracts were backwashed with a saturated aqueoussolution of sodium chloride (500 mL) and dried over sodium sulfate.Evaporation of the solvent in vacuo provided 12.0 g of an oil which wasdissolved in ether (80 mL) and treated with a saturated solution of HClin ether. A sticky product came out of solution, the solvent wasevaporated in vacuo and the resulting crude hydrochloride salt wasdissolved in water (200 mL). The acidic aqueous solution was extractedwith ethyl ether (2×100 mL) and then basified to pH 10 with 50% sodiumhydroxide aqueous solution. The basic aqueous solution was extractedwith ethyl ether (2×100 mL), the combined organic layers were dried oversodium sulfate and concentrated in vacuo to leave 7.20 g of the crudefree amino ether. The crude product was purified by chromatography onsilica gel 60 (70-230 mesh) with a mixture of ethylacetate-dichloromethane (1:1, v/v) as eluent to provide the pure freebase. The product was dissolved in ethyl ether (80 mL) and converted tothe monohydrochloride salt by adding a saturated solution of HCl inethyl ether (80 mL). A white product precipitated and this solid wascollected and dissolved in the minimum amount of warm ethyl alcohol;addition of a large volume of ethyl ether triggered crystallization. Thecrystals were collected to afford 2.30 g of the title compound, m.p.198-200° C., having the elemental analysis indicated in Table 1.

Example 3 (±)-Trans-[2-(4-Morpholinyl)-1-(4-Bromophenethoxy)]CyclohexaneMonohydrochloride Compound #3

(i) The starting trans-aminocyclohexanol is prepared according toexample 1.

(ii) To a chilled (0° C.) solution of(±)-trans-[2-morpholinyl)]cyclohexanol (3.0 g, 16.2 mmol) andtriethylamine (3.4 mL, 24 mmol) in dichloromethane (25 mL) was added viacannula a solution of methanesulfonyl chloride (1.55 mL, 20.0 mmol) indichloromethane (25 mL). The addition was completed in 5 min., thereaction mixture was stirred for another hour at 0° C. and then at roomtemperature for 2 hours. The reaction mixture was diluted withdichloromethane (50 mL) and washed with water (2×50 mL) and the combinedaqueous washings back extracted with dichloromethane (25 mL). Thecombined organic layers were dried over sodium sulfate and concentratedin vacuo to provide 4.7 g of the crude mesylate.

(iii) To sodium hydride, 80% oil dispersion, previously washed withhexanes (3×10 mL), (0.62 g, 25.8 mmol) in dry dimethylformamide (25 mL)was added via cannula a solution of 4-bromophenethylalcohol (4.0 g, 20mmol) in dimethylformamide (50 mL). Addition was followed by evolutionof gas and the reaction mixture was stirred at room temperature for 4hours. The mesylate as prepared in (ii) above was dissolved in drydimethylformamide (50 mL) and the resulting solution was added quickly(3 min.) via cannula to the slurry of alcoholate. The reaction mixturewas heated to 80° C. for 2 hours, then the temperature was reduced to35° C. and the reaction stirred overnight. The reaction mixture waspoured into ice-water (800 mL) and extracted with ethyl acetate (3×200mL). The combined organic extracts were backwashed with a saturatedaqueous solution of sodium chloride (150 mL) and dried over sodiumsulfate. Evaporation of the solvent in vacuo provided 7.4 g of an oilwhich was dissolved in ether (80 mL) was treated with a saturatedsolution of HCl in ether. An oil came out of solution, the solvent wasevaporated in vacuo and the residue was dissolved in water (100 mL). Theacidic aqueous solution was extracted with ethyl ether (2×50 mL) andthen basified to pH 10 with 50% sodium hydroxide aqueous solution. Thebasic aqueous solution was extracted with ethyl ether (2×50 mL), thecombined organic layers were dried over sodium sulfate and concentratedin vacuo to leave 3.67 g of the crude free amino ether. The crudeproduct was purified by chromatography on silica gel 60 (70-230 mesh)with a mixture of ethyl acetate-dichloromethane (1:1, v/v) as eluent toprovide the pure free base. The product was dissolved in ethyl ether (30mL) and converted to the monohydrochloride salt by adding a saturatedsolution of HCl in ethyl ether (30 mL). The solvent was evaporated andthe residue dissolved in the minimum amount of ethyl alcohol, additionof a large volume of ethyl ether triggered crystallization. The crystalswere collected to afford 1.31 g of the title compound, m.p. 148-151° C.,having the elemental analysis indicated in Table 1.

Example 4(±)-Trans-[2-(4-Morpholinyl)-1-[2-(2-Naphthoxy)Ethoxy)]CyclohexaneMonohydrochloride Compound #4

(i) The starting trans-aminocyclohexanol is prepared according toexample 1.

(ii) To a chilled (0° C.) solution of(±)-trans-[2-(4-morpholinyl)]cyclohexanol (3.0 g, 16.2 mmol) andtriethylamine (3.4 mL, 24 mmol) in dichloromethane (50 mL) was added viacannula a solution of methanesulfonyl chloride (1.55 mL, 20.0 mmol) indichloromethane (50 mL). The addition was completed in 10 min., thereaction mixture was stirred for another hour at 0° C. and then at roomtemperature for 4 hours. The dichloromethane mixture was washed withwater (2×50 mL) and the combined aqueous washings back extracted withdichloromethane (50 mL). The combined organic layers were dried oversodium sulfate and concentrated in vacuo to provide 4.3 g (100% yield)of the crude mesylate.

(iii) To sodium hydride, 80% oil dispersion, previously washed withhexanes (3×10 mL), (0.7 g, 29 mmol) in dry dimethylformamide (50 mL) wasadded via cannula a solution of 2-(2-naphthoxy)ethanol (3.76 g, 20.0mmol) in dry dimethylformamide (50 mL). Addition was followed byevolution of gas and the reaction mixture was stirred at roomtemperature for 90 min. The mesylate as prepared in (ii) above wasdissolved in dry dimethylformamide (50 mL) and the resulting solutionwas added quickly (3 min.) via cannula to the reaction mixture. Theresulting reaction mixture was heated overnight to 90° C. and thencooled to room temperature. The reaction mixture was poured intoice-water (800 mL) and extracted with ethyl acetate (3×200 mL). Thecombined organic extracts were backwashed with a saturated aqueoussolution of sodium chloride (300 mL) and dried over sodium sulfate.Evaporation of the solvent in vacuo provided 7.8 g of a yellow oil whichwas dissolved in ether (100 mL) and treated with a saturated solution ofHCl in ether (100 mL). The resulting precipitate was collected,partially solubilized in water (200 mL) and the heterogeneous aqueoussolution was extracted with ether (2×100 mL). The remaining insolublematerial was collected and recrystallized in boiling ethanol (75 mL) toprovide a first crop of the desired product. The acidic aqueous solutionwas basified to pH 10 with aqueous 50% NaOH and extracted with ether(2×50 mL). The combined organic extracts were dried over sodium sulfateand concentrated in vacuo to provide 1.6 g of the crude free aminoether. The product was purified by chromatography on silica gel 60(70-230 mesh) using a mixture of ethyl acetate-dichloromethane as eluentto yield 0.73 g of a pale yellow oil. The pure free base was thendissolved in ether (50 mL) and converted to the monohydrochloride saltby adding a saturated solution of HCl in ether (50 mL). The whiteprecipitate was collected and recrystallized in boiling ethanol (40 mL)to provide a second crop. Combination of the two crops afforded 1.03 gof the title compound, m.p. 235-237° C., having the elemental analysisindicated in Table 1.

Example 5(±)-Trans-[2-(4-Morpholinyl)-1-[2-(4-Bromophenoxy)Ethoxy)]]CyclohexaneMonohydrochloride Compound #5

(i) The starting trans-aminocyclohexanol is prepared according toexample 1.

(ii) To a chilled (0° C.) solution of(±)-trans-[2-(4-morpholinyl)]cyclohexanol (3.0 g, 16.2 mmol) andtriethylamine (3.4 mL, 24 mmol) in dichloromethane (50 mL) was added viacannula a solution of methanesulfonyl chloride (1.55 mL, 20.0 mmol) indichloromethane (50 mL). The addition was completed in 10 min., thereaction mixture was stirred for another hour at 0° C. and then at roomtemperature for 4 hours. The dichloromethane mixture was washed withwater (2×50 mL) and the combined aqueous washings back extracted withdichloromethane (50 mL). The combined organic layers were dried oversodium sulfate and concentrated in vacuo to provide 3.95 g (92% yield)of the crude mesylate.

(iii) To sodium hydride, 80% oil dispersion, previously washed withhexanes (3×10 mL), (0.63 g, 26 mmol) in dry dimethylformamide (50 mL)was added via cannula a solution of 2-(4-bromophenoxy)ethanol (4.34 g,20.0 mmol) in dry dimethylformamide (50 mL). Addition was followed byevolution of a gas and the reaction mixture was stirred at roomtemperature for 90 min. The mesylate as prepared in (ii) above wasdissolved in dry dimethylformamide (50 mL) and the resulting solutionwas added quickly (3 min.) via cannula to the reaction mixture. Thereaction mixture was heated to 90° C. for 90 min. and then thetemperature was reduced to 40° C. and the reaction was stirredovernight. The reaction mixture was poured into ice-water (800 mL) andextracted with ethyl acetate (3×200 mL). The combined organic extractswere backwashed with a saturated aqueous solution (300 mL) of sodiumchloride and dried over sodium sulfate. Evaporation of the solvent invacuo provided 8.35 g of a yellow oil which was dissolved in ether (100mL) and treated with a saturated solution of HCl in ether (100 mL). Theresulting white solid was collected and recrystallized in boilingethanol (150 mL) to yield 3.7 g (54% yield) of the pure title compound,m.p. 228-230° C., having the elemental analysis indicated in Table 1.

Example 6(±)-Trans-[2-(4-Morpholinyl)-1-(3,4-Dimethoxyphenethoxy)]CyclohexaneMonohydrochloride Compound #6

(i) The starting trans-aminocyclohexanol is prepared according toexample 1.

(ii) To a chilled (0° C.) solution of(±)-trans-[2-(4-morpholinyl)]cyclohexanol (3.0 g, 16.2 mmol) andtriethylamine (3.4 mL, 24 mmol) in dichloromethane (50 mL) was added viacannula a solution of methanesulfonyl chloride (1.55 mL, 20.0 mmol) indichloromethane (50 mL). The addition was completed in 10 min., thereaction mixture was stirred for another hour at 0° C. and then at roomtemperature for 4 hours. The dichloromethane mixture was washed withwater (2×50 mL) and the combined aqueous washings back extracted withdichloromethane (50 mL). The combined organic layers were dried oversodium sulfate and concentrated in vacuo to provide 4.18 g of the crudemesylate.

(iii) To sodium hydride, 80% oil dispersion, previously washed withhexanes (3×10 mL), (0.64 g, 27 mmol) in dry dimethylformamide (50 mL)was added via cannula a solution of 3,4-dimethoxyphenethyl alcohol (3.64g, 20.0 mmol) in dry dimethylformamide (50 mL). Addition was followed byevolution of a gas and the reaction mixture was stirred at roomtemperature for 90 min. The mesylate as prepared in (ii) above wasdissolved in dry dimethylformamide (50 mL) and the resulting solutionwas added quickly (3 min.) via cannula to the reaction mixture. Thereaction mixture was heated to 80° C. for 90 min. and then thetemperature was reduced to 40° C. and stirring continued overnight. Thereaction mixture was poured into ice-water (800 mL) and extracted withethyl acetate (3×200 mL). The combined organic extracts were backwashedwith a saturated aqueous solution of sodium chloride (300 mL) and driedover sodium sulfate. Evaporation of the solvent in vacuo provided 7.18 gof the crude product which was dissolved in ether (100 mL) and treatedwith a saturated solution of HCl in ether (100 mL). The solvent wasevaporated in vacuo and the residual oil was taken up with water (100mL) and extracted with ether (2×50 mL). The aqueous layer was basifiedto pH10 with 50% NaOH aqueous solution and extracted with ether (2×50mL). The combined organic layers were dried over sodium sulfate andconcentrated in vacuo. The crude product was purified by chromatographyon silica gel 60 (70-230 mesh) using a mixture of ethyl acetate anddichloromethane (1:1, v/v) as eluent to provide 2.8 g of a pale yellowoil. The free base was dissolved in ether (80 mL) and converted to themonohydrochloride salt by adding a saturated solution of HCl in ether(80 mL). The sticky precipitate was collected, dissolved in the minimumamount of ethanol and a large excess of ether was added to triggercrystallization of 2.24 g (36% yield) of the title compound, m.p.148-150° C., having the elemental analysis indicated in Table 1.

Example 7 (±)-Trans-[2-(1-Pyrrolidinyl)-1-(1-Naphthenethoxy)]CyclohexaneMonohydrochloride Compound #7

(i) Pyrrolidine (25 mL, 300 mmol), cyclohexene oxide (30 mL, 297 mmol)and water (10 mL) were refluxed for 3 h. GC analysis showed the reactionto be complete. The cooled mixture was partitioned between saturatedNaOH solution (10 mL) and ether (150 mL). The aqueous layer wasbackwashed with ether (2×100 mL) and the combined ether layers weredried over sodium sulfate. The ether was removed in vacuo to leave ayellow oil. The crude product was purified by vacuum distillation (b.p.66-69° C. at full vacuum) to give a clear liquid (43.9 g). Yield 87%.

(ii) To a chilled (0° C.) solution of(±)-trans-[2-(pyrrolidinyl)]cyclohexanol (2.74 g, 16.2 mmol) andtriethylamine (3.4 mL, 24 mmol) in dichloromethane (50 mL) was added viacannula a solution of methanesulfonyl chloride (1.55 mL, 20.0 mmol) indichloromethane (50 mL). The addition was completed in 10 min., thereaction mixture was washed with water (2×50 mL) and the combinedaqueous washings back extracted with dichloromethane (50 mL). Thecombined organic layers were dried over sodium sulfate and concentratedin vacuo to provide 3.24 g of the crude mesylate.

(iii) To sodium hydride, 80% oil dispersion, previously washed withhexanes (3×10 ml), (0.64 g, 27 mmol) in dry dimethylformamide (50 mL)was added via cannula a solution of 1-naphthenethanol (3.64 g, 20.0mmol) in dry dimethylformamide (50 mL). Addition was followed byevolution of a gas and the reaction mixture was stirred at roomtemperature for 90 min. The mesylate as prepared in (ii) above wasdissolved in dry dimethylformamide (50 mL) and the resulting solutionwas added quickly (3 min.) via cannula to the reaction mixture. Thereaction mixture was heated to 80° C. for 90 min. and then itstemperature was reduced to 40° C. and it was stirred overnight. Thereaction mixture was poured into ice-water (800 mL) and extracted withethyl acetate (3×200 mL). The combined organic extracts were backwashedwith a saturated aqueous solution with sodium chloride (300 mL) anddried over sodium sulfate. Evaporation of the solvent in vacuo provided9.00 g of the crude product which was dissolved in ether (50 mL) andtreated with a saturated solution of HCl in ether (50 mL). The solventwas evaporated in vacuo and the residual oil was taken up with water(100 mL) and extracted with ether (2×50 mL). The aqueous layer wasbasified to pH10 with 50% NaOH aqueous solution and extracted with ether(2×50 mL). The combined organic layers were dried over sodium sulfateand concentrated in vacuo. The crude product was purified bychromatography on silica gel 60 (70-230 mesh) using a mixture of ethylmethanol and chloroform (2:8, v/v) as eluent. The free amino ether waspartially dissolved in ether (80 mL), insoluble materials were filteredoff, and then a saturated solution of HCl in ether (80 mL) was added tothe filtrate. The solvent was evaporated in vacuo, the residue wasdissolved in acetone and addition of aliquots of ether triggered slowcrystallization. 2 crops of the title compound (0.88 g), m.p. 103-105°C. were collected, having the elemental analysis indicated in Table 1.

Example 8(±)-Trans-[2-(4-Morpholinyl)-1-(2-(Benzo[b]Thiophen-3-yl)Ethoxy)]CyclohexaneMonohydrochloride Compound #8

(i) The starting trans-aminocyclohexanol is prepared according toexample 1.

(ii) To a chilled (0° C.) solution of(±)-trans-[2-(4-morpholinyl)]cyclohexanol (3.0 g, 16.2 mmol) andtriethylamine (3.4 mL, 24 mmol) in dichloromethane (50 mL) was added viacannula a solution of methanesulfonyl chloride (1.55 mL, 20.0 mmol) indichloromethane (50 mL). The addition was completed in 5 min., thereaction mixture was stirred for another hour at 0° C. and then at roomtemperature for 3 hours. The reaction mixture was washed with water(3×30 mL) and the combined aqueous washings back extracted withdichloromethane (50 mL). The combined organic layers were dried oversodium sulfate and concentrated in vacuo to provide 5.25 g of the crudemesylate.

(iii) To sodium hydride, 80% oil dispersion, previously washed withhexanes (3×10 mL), (0.60 g, 25 mmol) in dry dimethylformamide (50 mL)was added via cannula a solution of 2-(benzo[b]thiophen-3-yl)ethanol(3.56 g, 20.0 mmol) in dry dimethylformamide (50 mL). Addition wasfollowed by evolution of gas and the reaction mixture was stirred atroom temperature for 3 hours. The mesylate as prepared in (ii) above wasdissolved in dry dimethylformamide (50 mL) and the resulting solutionwas added quickly (2 min.) via cannula to the reaction mixture. Thereaction mixture was heated to 75° C. for 2 hours, then the temperaturewas reduced to 65° C. and stirring continued overnight. The reactionmixture was poured into ice-water (800 mL) and extracted with ethylacetate (3×200 mL). The combined organic extracts were backwashed with asaturated aqueous solution (300 mL) of sodium chloride and dried oversodium sulfate. Evaporation of the solvent in vacuo provided 7.7 g of anoil which was dissolved in ether (100 mL) and treated with a saturatedsolution of HCl in ether (100 mL). An oil precipitated from thesolution, the solvent was evaporated in vacuo and the resulting crudehydrochloride salt was dissolved in water (200 ml). The acidic aqueoussolution was extracted with ethyl ether (2×100 mL) and then basified topH 10 with aqueous 50% sodium hydroxide. The basic aqueous solution wasextracted with ethyl ether (3×100 mL), the combined organic layers weredried over sodium sulfate and concentrated in vacuo to leave 3.30 g ofthe crude free aminoether. The crude product was purified bychromatography on silica gel 60 (70-230 mesh) with a mixture of ethylacetate and dichloromethane (1:1, v/v) as eluent to provide the freebase. The product was dissolved in ethyl ether (100 mL) and converted tothe monohydrochloride salt by adding a saturated solution of HCl inethyl ether (100 mL). The solvent was evaporated in vacuo and theresidue was dissolved in the minimum amount of boiling methanol toprovide a first crop (0.7 g) of crystalline product on cooling. Additionof diethyl ether to the methanol filtrate provided a second crop (0.55g). The two crops were combined to yield 1.25 g of the title compound,m.p. 158-160° C., having the elemental analysis indicated in Table 1.

Example 9(±)-Trans-[2-(4-Morpholinyl)-1-(2-(Benzo[b]Thiophen-4-yl)Ethoxy)]CyclohexaneMonohydrochloride Compound #9

(i) The starting trans-aminocyclohexanol is prepared according toexample 1.

(ii) To a chilled (0° C.) solution of(±)-trans-[2-(4-morpholinyl)]cyclohexanol (3.0 g, 16.2 mmol) andtriethylamine (3.4 mL, 24.0 mmol) in dichloromethane (50 mL) was addedvia cannula a solution of methanesulfonyl chloride (1.55 mL, 20.0 mmol)in dichloromethane (50 mL). The addition was completed in 5 min., thereaction mixture was stirred for another hour at 0° C. and then at roomtemperature for 3 hours. The reaction mixture was washed with water(2×30 mL) and the combined aqueous washings back extracted withdichloromethane (50 mL). The combined organic layers were dried oversodium sulfate and concentrated in vacuo to provide 4.24 g of the crudemesylate.

(iii) To sodium hydride, 80% oil dispersion, previously washed withhexanes (3×10 mL), (0.60 g, 25 mmol) in dry dimethylformamide (50 mL)was added via cannula a solution of 2-(benzo[b]thiophen-4-yl)ethanol(3.56 g, 20.0 mmol) in dry dimethylformamide (50 mL). Addition wasfollowed by evolution of a gas and the reaction mixture was stirred atroom temperature for 3 hours. The mesylate as prepared in (ii) above wasdissolved in dry dimethylformamide (50 mL) and the resulting solutionwas added quickly (2 min.) via cannula to the reaction mixture. Thereaction mixture was heated to 85° C. for 2 hours, then the temperaturewas reduced to 40° C. and the reaction stirred overnight. The reactionmixture was poured into ice-water (800 mL) and extracted with ethylacetate (3×200 mL). The combined organic extracts were backwashed with asaturated aqueous solution (300 mL) of sodium chloride and dried oversodium sulfate. Evaporation of the solvent in vacuo provided 8.2 g of anoil which was dissolved in ether (100 mL) and treated with a saturatedsolution of HCl in ether (100 mL). An oil precipitated and the solventwas evaporated in vacuo and the resulting crude hydrochloride salt wasdissolved in water (200 mL). The acidic aqueous solution was extractedwith ethyl ether (2×100 mL) and then basified to pH 10 with an aqueoussolution of sodium hydroxide (50% w/v). The basic aqueous solution wasextracted with ethyl ether (3×100 mL), the combined organic layers weredried over sodium sulfate and concentrated in vacuo to leave 3.0 g ofthe crude free aminoether. The crude product was purified bychromatography on silica gel 60 (70-230 mesh) with a mixture of ethylacetate-dichloromethane (1:1, v/v) as eluent to provide the pure freebase. The product was dissolved in ethyl ether (50 mL) and converted tothe monohydrochloride salt by adding a saturated solution of HCl inethyl ether (50 mL). The solvent was evaporated in vacuo, the residuewas dissolved in the minimum amount of cold ethanol and addition ofether triggered formation of crystals (1.17 g), m.p. 178-180° C., havingthe elemental analysis indicated in Table 1.

Example 10(±)-Trans-[2-(4-Morpholinyl)-1-(3-Bromophenethoxy)]CyclohexaneMonohydrochloride Compound #10

(i) The starting trans-aminocyclohexanol is prepared according toexample 1.

(ii) To a chilled (0° C.) solution of(±)-trans-[2-(4-morpholinyl)]cyclohexanol (3.0 g, 16.2 mmol) andtriethylamine (3.4 mL, 24 mmol) in dichloromethane (50 mL) was added viacannula a solution of methanesulfonyl chloride (1.55 mL, 20.0 mmol) indichloromethane (50 mL). The addition was completed in 5 min., thereaction mixture was stirred for another hour at 0° C. and then at roomtemperature for 3 hours. The reaction mixture was washed with water(2×30 mL) and the combined aqueous washings back extracted withdichloromethane (50 mL). The combined organic layers were dried oversodium sulfate and concentrated in vacuo to provide 5.4 g of the crudemesylate.

(iii) To sodium hydride, 80% oil dispersion, previously washed withhexanes (3×10 mL), (0.60 g, 25 mmol) in dry dimethylformamide (50 mL)was added via cannula a solution of 3-bromophenethyl alcohol (4.0 g, 20mmol) in dry dimethylformamide (50 mL). Addition was followed byevolution of a gas and the reaction mixture was stirred at roomtemperature for 3 hours. The mesylate as prepared in (ii) above wasdissolved in dry dimethylformamide (50 mL) and the resulting solutionwas added quickly (2 min.) via cannula to the reaction mixture. Thereaction mixture was heated to 85° C. for 2 hours, then the temperaturewas reduced to 45° C. and the reaction stirred overnight. The reactionmixture was poured into ice-water (800 mL) and extracted with ethylacetate (3×200 mL). The combined organic extracts were backwashed with asaturated aqueous solution of sodium chloride (300 mL) and dried oversodium sulfate. Evaporation of the solvent in vacuo provided 8.0 g of anoil which was dissolved in ether (100 mL) and treated with a saturatedsolution of HCl in ether (100 mL). An oil precipitated and the solventwas evaporated in vacuo and the resulting crude hydrochloride salt wasdissolved in water (200 mL). The acidic aqueous solution was extractedwith ethyl ether (2×100 mL) and then basified to pH 10 with an aqueoussolution of sodium hydroxide (50% w/v). The basic aqueous solution wasextracted with ethyl ether (3×100 mL), the combined organic layers weredried over sodium sulfate and concentrated in vacuo to leave 2.9 g ofthe crude free aminoether. The crude product was purified bychromatography on silica gel 60 (70-230 mesh) with a mixture of ethylacetate-dichloromethane (1:1, v/v) as eluent to provide the pure freebase. The product was dissolved in ethyl ether (50 mL) and converted tothe monohydrochloride salt by adding saturated solution of HCl in ethylether (50 mL). The solvent was evaporated in vacuo, the residue wasdissolved in the minimum amount of cold ethanol and addition of ethertriggered formation of crystals (0.53 g), m.p. 145-148° C., having theelemental analysis indicated in Table 1.

Example 11(±)-Trans-[2-(4-Morpholinyl)-1′-(2-Bromophenethoxy)]CyclohexaneMonohydrochloride Compound #11

(i) The starting trans-aminocyclohexanol is prepared according toexample 1.

(ii) To a chilled (0° C.) solution of(±)-trans-[2-(4-morpholinyl)]cyclohexanol (3.0 g, 16.2 mmol) andtriethylamine (3.4 mL, 24.0 mmol) in dichloromethane (50 mL) was addedvia cannula a solution of methanesulfonyl chloride (1.55 mL, 20.0 mmol)in dichloromethane (50 mL). The addition was completed in 5 min. thereaction mixture was stirred for another hour at 0° C. and then at roomtemperature for 3 hours. The reaction mixture was washed with water(2×30 mL) and the combined aqueous washings back extracted withdichloromethane (50 mL). The combined organic layers were dried oversodium sulfate and concentrated in vacuo to provide 5.9 g of the crudemesylate.

(iii) To sodium hydride, 80% oil dispersion, previously washed withhexanes (3×10 mL), (0.60 g, 25 mmol) in dry dimethylformamide (50 mL)was added via cannula a solution of 2-bromophenethyl alcohol (4.0 g, 20mmol) in dry dimethylformamide (50 mL). Addition was followed byevolution of a gas and the reaction mixture was stirred at roomtemperature for 3 hours. The mesylate as prepared in (ii) above wasdissolved in dry dimethylformamide (50 mL) and the resulting solutionwas added quickly (2 min.) via cannula to the reaction mixture. Thereaction mixture was heated to 85° C. for 2 hours, then the temperaturewas reduced to 45° C. and the reaction stirred overnight. The reactionmixture was poured into ice-water (800 mL) and extracted with ethylacetate (3×200 mL). The combined organic extracts were backwashed with asaturated aqueous solution of sodium chloride (300 mL) and dried oversodium sulfate. Evaporation of the solvent in vacuo provided 8.4 g of anoil which was dissolved in 1.0 M HCl aqueous solution (50 mL), thevolume was adjusted to 200 mL with water and the pH adjusted to pH 2with 1.0 M HCl aqueous solution. The acidic aqueous solution wasextracted with ethyl ether (3×100 mL) and then basified to pH 10 with50% aqueous sodium hydroxide solution. The basic aqueous solution wasextracted with ethyl ether (3×100 mL), the combined organic layers weredried over sodium sulfate and concentrated in vacuo to leave 2.8 g ofthe crude free aminoether. The crude product was purified bychromatography on silica gel 60 (70-230 mesh) with a mixture of ethylacetate-dichloromethane (1:1, v/v) as eluent to provide the pure freebase. The product was dissolved in ethyl ether (50 mL) and converted tothe monohydrochloride salt by adding saturated solution of HCl in ethylether (50 mL). The solvent was evaporated in vacuo, the residue wasdissolved in the minimum amount of cold ethanol and addition of ethertriggered formation of crystals which were collected in two crops (0.74g), m.p. 140-142° C., having the elemental analysis indicated in Table1.

Example 12(±)-Trans-[2-(4-Morpholinyl)-1-(3-(3,4-Dimethoxyphenyl)-1-Propoxy)]CyclohexaneMonohydrochloride Compound #12

(i) The starting trans-aminocyclohexanol is prepared according toexample 1.

(ii) To a chilled (0° C.) solution of(±)-trans-[2-(4-morpholinyl)]cyclohexanol (3.0 g, 16.2 mmol) andtriethylamine (3.4 mL, 24 mmol) in dichloromethane (50 mL) was added viacannula a solution of methanesulfonyl chloride (1.55 mL, 20.0 mmol) indichloromethane (50 mL). The addition was completed in 10 min., thereaction mixture was stirred for another hour at 0° C. and then at roomtemperature for 4 hours. The dichloromethane mixture was washed withwater (2×50 mL) and the combined aqueous washings back extracted withdichloromethane (50 mL). The combined organic layers were dried oversodium sulfate and concentrated in vacuo to provide the crude mesylate.

(iii) To sodium hydride, 80% oil dispersion, previously washed withhexanes (3×10 mL), (0.6 g, 27 mmol) in dry dimethylformamide (50 mL) wasadded via cannula a solution of 3-(3,4-dimethoxyphenyl)-1-propanol (3.93g, 20.0 mmol) in dry dimethylformamide (50 mL). Addition was followed byevolution of a gas and the reaction mixture was stirred at roomtemperature for 90 min. The mesylate as prepared in (ii) above wasdissolved in dry dimethylformamide (50 mL) and the resulting solutionwas added quickly (3 min.) via cannula to the reaction mixture. Thereaction mixture was heated to 90° C. for 90 min. and then thetemperature was reduced to 45° C. and stirring continued overnight. Thereaction mixture was poured into ice-water (800 mL) and extracted withethyl acetate (3×200 mL). The combined organic extracts were backwashedwith a saturated aqueous solution of sodium chloride (300 mL) and driedover sodium sulfate. Evaporation of the solvent in vacuo provided 8.5 gof the crude product which was dissolved in 15% HCl aqueous solution(200 mL) and extracted with ether (2×100 mL). The aqueous layer wasbasified to pH10 with 50% NaOH aqueous solution and extracted with ether(2×100 mL). The combined organic layers were dried over sodium sulfateand concentrated in vacuo. The crude product was purified bychromatography on silica gel 60 (70-230 mesh) using a mixture of ethylacetate and dichloromethane (1:1, v/v) as eluent to provide the freebase which was dissolved in ether (80 mL) and converted to themonohydrochloride salt by adding a saturated solution of HCl in ether(80 mL). The sticky precipitate was collected, dissolved in the minimumamount of warm ethanol and a large excess of ether was added to triggercrystallization of the title compound, m.p. 175-177° C., having theelemental analysis indicated in Table 1.

Example 13 (±)-trans-[2-[bis(2Methoxyethyl)amino]-1-(2-naphthenethoxy)]cyclohexane monohydrochlorideCompound #13

(i) Bis-(2-methoxyethyl)amine (25 mL, 169 mmol) and cyclohexene oxide(17.2 mL, 170 mmol) were mixed in water (5 mL) and the resulting mixturewas refluxed for 30 hours. The cooled reaction mixture was partitionedbetween 10% NaOH aqueous (200 mL) and diethyl ether (200 mL). Theaqueous layer was extracted twice more with diethyl ether (2×100 mL),the combined organic layers were washed with water (8 mL) and dried oversodium sulfate. The solvent was evaporated in vacuo to provide the crudeproduct which was vacuum distilled to provide 26.4 g of pure colorlessoil.

(ii) To a chilled (0° C.) solution of(±)-trans-2-[bis(2-methoxyethyl)amino]cyclohexanol) 4.63 g, 20.00 mmol)and triethylamine (3.4 mL, 24.00 mmol) in dichloromethane (50 mL) wasadded via cannula a solution of methanesulfonyl chloride (1.55 mL, 20.00mmol) in dichloromethane (50 mL). The additional was completed in 5min., the reaction mixture was stirred for another hour at 0° C. andthen at room temperature for 4 hours. The reaction mixture was washedwith water (2×30 mL) and the combined aqueous washings backextractedwith dichloromethane (50 mL). The combined organic layers were driedover sodium sulfate and concentrated in vacuo to provide 4.87 g of thecrude mesylate.

(iii) To sodium hydride, 80% oil dispersion, previously washed withhexanes (3×10 mL), (0.60 g, 25.00 mmol) in anhydrous dimethylformamide(50 mL) was added via cannula a solution of 2-naphthenethanol (3.4 g,20.00 mmol) in anhydrous dimethylformamide (50 mL). Addition wasfollowed by hydrogen bubbling, the reaction mixture was stirred at roomtemperature for 90 min. The mesylate as prepared in (ii) above wasdissolved in dry dimethylformamide (50 mL) and the resulting solutionwas added quickly (3 min.) via cannula to the reaction mixture. Thereaction mixture was heated up to 90° C. in 2 hours, then thetemperature was reduced to 40° C. and the reaction stirred overnight.The reaction mixture was poured into ice-water (800 mL) and extractedwith ethyl acetate (3×200 mL). The combined organic extracts werebackwashed with a sodium chloride saturated aqueous solution (300 mL)and dried over sodium sulfate. Evaporation of the solvent in vacuoprovided 8.1 g of an oil which was dissolved in 1M HCl aqueous solution(50 mL) and the volume completed to 200 mL with water. The acidicaqueous solution was extracted with diethyl ether (2×100 mL) and thenbasified to pH 10 with 50% sodium hydroxide aqueous solution. The basicaqueous solution was extracted with ethyl ether (2×100 mL), the combinedorganic layers were dried over sodium sulfate and concentrated in vacuoto leave 3.58 g of the crude free aminoether. The crude product waspurified by chromatography column using silica gel 60, 70-230 mesh fromBDH Inc. with a mixture of methanol and dichloromethane (2:8, v/v) aseluent to provide the pure free base. The product was dissolved indiethyl ether (50 mL) and converted to the monohydrochloride salt byadding etheral HCl (50 mL). The solvent was evaporated in vacuo to yield0.75 g of the title compound (not recrystallized).

Example 14 (1R,2R)/(1S,2S)-2-(4-Morpholinyl)-1-(3,4-dichlorophenethoxy)cyclohexane monohydrochloride Compound #14

The basic overall approach used to synthesize this compound is analogousto that shown in FIG. 1.

(i) (1R,2R)/(1S,2S)-2-(4-Morpholinyl)cyclohexanol: A mixture ofcyclohexene oxide (206.5 mL, 2 mol, 98%) and morpholine (175 mL, 2 mol)in water (60 mL) was refluxed for 3.5 h. Morpholine (5.3 mL) was addedto the reaction mixture, which was then further refluxed for 1.5 h. inorder to complete the reaction. The cooled reaction mixture was thenpartitioned between 40% NaOH aqueous solution (100 mL) and diethyl ether(200 mL). The aqueous layer was separated from the organic layer andextracted twice more with diethyl ether (2×100 mL). The combined organicextracts were dried over sodium sulfate and the solvent was evaporatedin vacuo. Vacuum distillation yielded 342.3 g (92.4%) of the titlecompound.

(ii) To a chilled (0° C.) solution of(1R,2R)/(1S,2S)-2-(4-morpholinyl)cyclohexanol (40.76 g, 0.22 mol) andtriethylamine (36.60 mL, 0.26 mol) in dichloromethane (400 mL) was addeddropwise a solution of methanesulfonyl chloride (20.53 mL, 0.26 mol) indichloromethane (50 mL). The reaction mixture was stirred at 0° C. for45 min. and then at room temperature for 3 hours. The reaction mixturewas then washed with water (2×100 mL); the combined washings wereback-extracted with dichloromethane (100 mL). The combined organicextracts were dried over sodium sulfate and the solvent was evaporatedin vacuo to yield the crude mesylate suitable for the next step withoutany further purification.

(iii) 3,4-Dichlorophenethyl alcohol: To a solution of lithium aluminumhydride (7.79 g, 195 mmol) in anhydrous diethyl ether (435 mL) was addedslowly as a powder, via a solid dropping funnel, 3,4-dichlorophenylacetic acid (27.20 g, 130 mmol). When the addition was completed, thereaction mixture was refluxed for 12 hours. The reaction was quenched bycautious addition of saturated sodium sulfate aqueous solution (20 mL),the resulting insoluble was then filtered off and the filtrate wasconcentrated in vacuo to yield 25.09 g of the desired alcohol.

(iv) To NaH (6.00 g, 0.2 mol, 80% dispersion in oil) in anhydrousethylene glycol dimethyl ether (200 mL) was added a solution of3,4-dichlorophenethyl alcohol (38.87 g, 0.2 mol) in anhydrous ethyleneglycol dimethyl ether (100 mL). The resulting mixture was stirred for 3hours at ambient temperature under argon atmosphere.

(v) The mesylate (ii) in anhydrous ethylene glycol dimethyl ether (100mL) was added quickly to the alkoxide (iv) and the resulting reactionmixture was readily refluxed for 16 hours. To the cooled reactionmixture was added water (200 mL) and the organic solvent was evaporatedin vacuo. The resulting aqueous solution was further diluted with water(200 mL) and the pH was adjusted to pH 1.5 with 10% HCl aqueoussolution. The acidic aqueous layer was extracted with diethyl ether (500mL) to eliminate the unreacted 3,4-dichlorophenethyl alcohol. Furtherbasification of the aqueous layer with 5M NaOH aqueous solution to pH5.7 followed by extraction with diethyl ether provided the crude titlecompound contaminated with some remaining mesylate (ii). The solvent ofthe organic extract at pH 5.7 was evaporated in vacuo, the residue wasthen refluxed in a mixture of ethanol-water (1:1, v/v, 200 mL) in thepresence of sodium hydride (4.12 g, 0.1 mol) for 2 hours in order tohydrolyzed the remaining mesylate. The cooled reaction mixture wasdiluted with water (300 mL) and the organic solvent was evaporated invacuo. The pH of the residual aqueous solution was adjusted to pH 5.7with 6M HCl aqueous solution followed by extraction with diethyl ether(700 mL). The organic extract was concentrated in vacuo to yield thepure aminoether. The residual product was then partitioned between 1MHCl aqueous solution (300 mL) and dichloromethane (300 mL). The acidicaqueous solution was extracted twice more with dichloromethane (2×300mL). The combined organic layers were dried over sodium sulfate, thesolvent was evaporated in vacuo and the residue was recrystallized froma mixture of ethanol-hexanes (3:7, v/v, 700 mL) to yield 49.3 g of thetitle compound, having the elemental analysis indicated in Table 1.

Example 15(1R,2R)/(1S,2S)-2-(3-Ketopyrrolidinyl)-1-(1-naphthenethoxy)cyclohexanemonohydrochloride Compound #15

Synthesis of Compound #15 follows the sequence of reactions shown inFIG. 4A and FIG. 4B, and is described in detail below.

(i) N-Benzyloxycarbonyl-3-pyrrolidinol: To a chilled (−60° C.) solutionof (R)-(+)-3-pyrrolidinol (20.0 g, 98%, 224.9 mmol) and triethylamine(79.2 mL, 99%, 562 mmol) in dichloromethane (200 mL) was added dropwisea solution of benzyl chloroformate (33.8 mL, 95%, 224.9 mmol) indichloromethane (80 mL). After the addition was completed within 45 min,the reaction mixture (a yellow suspension) was allowed to warm up toroom temperature and was stirred under argon at room temperatureovernight. The reaction mixture was then quenched with 1M HCl aqueoussolution (350 mL) and the organic layer was collected. The acidicaqueous layer was extracted with dichloromethane (2×150 mL) and thecombined organic layers were dried over sodium sulfate. Evaporation invacuo of the solvent provided 59.62 g of pale yellow oil, which wasfurther pumped under high vacuum for 15 min to yield 58.23 g (17% overtheoretical yield) of the crude title compound suitable for the nextstep without any further purification.

(ii) N-Benzyloxycarbonyl-3-pyrrolidinone: To a chilled (−60° C.)solution of oxalyl chloride (23 mL, 98%, 258.6 mmol) in dichloromethane(400 mL) was added dropwise a solution of anhydrous dimethyl sulfoxide(36.7 mL, 517.3 mmol) in dichloromethane (20 mL) at such a rate to keepthe temperature below −40° C. The reaction mixture was then stirred at−60° C. for 15 min. Then a solution ofN-benzyloxycarbonyl-3-pyrrolidinol (58.22 g, step i, no more than 224.9mmol) in dichloromethane (80 mL) was added dropwise, keeping thereaction mixture temperature below −50° C. The reaction mixture was thenstirred at −60° C. for 30 min before adding triethylamine (158.3 mL,99%, 1.125 mol). The resulting mixture was allowed to warm up to roomtemperature and then washed with water (600 mL), 1M HCl aqueous solution(580 mL) and water (400 mL). The organic layer was dried over sodiumsulfate and concentrated in vacuo to leave 54.5 g of amber oil, whichwas further pumped under high vacuum with stirring at room temperaturefor 25 min. to give 52.08 g (5.6% over theoretical yield) of the crudetitle compound suitable for the next step without any furtherpurification.

(iii) 7-Benzyloxycarbonyl-1,4-dioxa-7-azaspiro[4.4]nonane: A mixture ofN-benzyloxycarbonyl-3-pyrrolidinone (51.98 g, step ii, no more than224.9 mmol) and ethylene glycol (18.8 mL, 99+%, 337.4 mmol) in toluene(180 mL) with a catalytic amount of p-toluenesulfonic acid monohydrate(1.04 g, 5.4 mmol) was refluxed in a Dean & Stark apparatus for 16hours. The reaction mixture was then diluted with more toluene (250 mL)and washed with saturated sodium bicarbonate aqueous solution (150 mL)and saturated sodium chloride aqueous solution (2×150 mL). The combinedaqueous layers were back-extracted with toluene (100 mL). The combinedorganic layers were dried over sodium sulfate and concentrated in vacuoto leave 79.6 g of dark oil. The crude product was dissolved in ethanol(500 mL), and running it through a bed of activated carbon (80 g),decolorized the resulting solution. The charcoal was washed with moreethanol (1000 mL) and toluene (500 mL). The filtrate was concentrated invacuo and further pumped under high vacuum for 1 hour to yield 63.25 g(6.8% over theoretical yield) of the crude title compound suitable forthe next step without any further purification.

(iv) 1,4-Dioxa-7-azaspiro[4.4]nonane: A mixture of7-benzyloxycarbonyl-1,4-dioxa-7-azaspiro[4.4]nonane (34.79 g, step iii,no more than 123.7 mmol) and 10% Pd—C (13.9 g) in ethanol (90 mL) washydrogenolyzed (60 psi) in a Parr shaker apparatus at room temperaturefor 1.5 hour. The catalyst was filtered off, the solvent was evaporatedin vacuo and the residue was pumped under high vacuum for 20 min. toyield 15.86 g of the title compound (yield 99.3%).

(v) (1R,2R)/(1S,2S)-2-(1,4-Dioxa-7-azaspiro[4.4]non-7-yl)cyclohexanol: Amixture of 1,4-dioxa-7-azaspiro[4.4]nonane (23.54 g, step iv, no morethan 182 mmol), cyclohexene oxide (22.6 mL, 98%, 219 mmol) and water(7.8 mL) was heated at 80° C. for 2 hours. The reaction mixture was thenpartitioned between 40% sodium hydroxide aqueous solution (60 mL) anddiethyl ether (120 mL). The basic aqueous layer was extracted twice morewith diethyl ether (2×120 mL). The combined organic extracts were driedover sodium sulfate and concentrated in vacuo. The residue was thenpumped under high vacuum at 50° C. for 1 hour under stirring (to removethe excess of cyclohexene oxide) to yield 32.79 g of the crude titlecompound (yield 79.3%).

(vi) To a chilled (0° C.) solution of(1R,2R)/(1S,2S)-2-(1,4-dioxa-7-azaspiro[4.4]non-7-yl)cyclohexanol (27.47g, 120 mmol, step v) and triethylamine (15.86 g, 156 mmol) indichloromethane (240 mL) was added dropwise methanesulfonyl chloride(18.23 g, 156 mmol). The reaction mixture was stirred at 0° C. for 45min. and then at room temperature for 3 hours. The reaction mixture wasthen washed with a mixture of water-saturated sodium bicarbonate aqueoussolution (1:1, v/v, 120 mL). The washing layer was collected and wasback-extracted with dichloromethane (120 mL). The combined organicextracts were dried over sodium sulfate, the solvent was evaporated invacuo and the residue was pumped under high vacuum for 4 hours to yieldthe crude mesylate suitable for the next step without any furtherpurification.

(vii) To sodium hydride (4.32 g, 144 mmol) suspended in anhydrousethylene glycol dimethyl ether (80 mL) was added a solution of1-naphthenethanol (25.31 g, 144 mmol) in anhydrous ethylene glycoldimethyl ether (80 mL). The resulting mixture was then stirred at roomtemperature for 4 hours.

(viii)(1R,2R)/(1S,2S)-2-[1,4-dioxa-7-azaspiro[4.4]non-7-yl]-1-(1-naphthenethoxy)cyclohexane:A solution of mesylate (vi) in anhydrous ethylene glycol dimethyl ether(80 mL) was added quickly to the alkoxide (vii) and the resultingmixture was readily heated to reflux under argon for 66 hours. Thecooled reaction mixture was quenched with water (200 mL) and the organicsolvent was evaporated in vacuo. The remaining aqueous solution wasdiluted with water (500 mL) and acidified with 10% HCl aqueous solutionto pH 0.5. The acidic aqueous layer was extracted with diethyl ether(2×500 mL) in order to extract unreacted 1-naphthenethanol. The pH ofthe aqueous solution was adjusted to pH 4.8 with 5M NaOH aqueoussolution and then extracted with diethyl ether (600 mL). The aqueoussolution was further basified to pH 5.7 and extracted with diethyl ether(600 mL). The same procedure was repeated at pH 6.5 and 12.1. Analysisby gas chromatography of the different ether extracts showed thatorganic extracts at pH 4.8, 5.7 and 6.5 contained the title compoundwhereas ether extract at pH12.1 contained only unknown impurities. Theorganic extracts at pH 4.8, 5.7 and 6.5 were combined and dried oversodium sulfate. The solvent was evaporated in vacuo and the residue waspumped under high vacuum for 3.5 hours to yield 35.82 g (75% yield) ofthe title compound suitable for the next step without any furtherpurification.

(ix)(1R,2R)/(1S,2S)-2-(3-Ketopyrrolidinyl)-1-(1-naphthenethoxy)cyclohexanemonohydrochloride: A solution of(1R,2R)/(1S,2S)-2-[1,4-dioxa-7-azaspiro[4.4]non-7-yl]-1-(1-naphthenethoxy)cyclohexane(13.73 g, 36.0 mmol, step vi) with 6M HCl aqueous solution (50 mL) in2-butanone (200 mL) was refluxed for 12 hours. The butanone wasevaporated in vacuo and the residual aqueous solution was diluted to 250mL with water. The aqueous solution was extracted with diethyl ether(2×200 mL) and then with dichloromethane (2×200 mL). The pooleddichloromethane extracts were dried over sodium sulfate and the solventwas evaporated in vacuo. The residual oil was azeotropically dried withtoluene. The resulting sticky product was vigorously stirred overnightin diethyl ether (500 mL) with occasional scratching to triggercrystallization of the reaction product. The resulting solid wascollected and solubilized in a small amount of dichloromethane (˜10 mL),addition of a large quantity of diethyl ether (˜400 mL) triggeredrecrystallization. The solid was collected, dried under high vacuum for3 hours to yield 9.3 g (76% yield) of the title compound, having theelemental analysis indicated in Table 1.

Example 16(1R,2R)/(1S,2S)-2-(1-Acetylpiperazinyl)-1-(2-naphthenethoxy)cyclohexanemonohydrochloride Compound #16

Compound #16 was prepared according to a procedure similar as the onedepicted in FIG. 1 and further detailed in Example 14.

(i) (1R,2R)/(1S,2S)-2-(1-Acetylpiperazinyl)-1-cyclohexanol: A mixture of1-acetylpiperazine (5 g, 39 mmol) and cyclohexene oxide (3.95 mL, 39mmol) in water (1.2 mL) was refluxed for 16 hours. The cooled reactionmixture was partitioned between 40% NaOH aqueous solution (20 mL) anddiethyl ether (2×20 mL). The combined organic layers were dried oversodium sulfate and the solvent was evaporated in vacuo to yield 7.63 gof the title compound as white crystals (87% yield)

(ii) To a chilled (0° C.) solution of(1R,2R)/(1S,2S)-2-(1-acetylpiperazinyl)-1-cyclohexanol (3.65 g, 16.2mmol) and triethylamine (3.4 mL, 24 mmol) in dichloromethane (50 mL) wasadded dropwise a solution of methanesulfonyl chloride (1.55 mL, 20 mmol)in dichloromethane (50 mL). The reaction mixture was stirred at 0° C.for one hour and then allowed to warm up to ambient temperature. Thereaction mixture was then washed with water (2×50 mL) and the combinedwashings were back-extracted with dichloromethane (50 mL). The combinedorganic layers were dried over sodium sulfate and the solvent wasevaporated in vacuo to yield the crude mesylate suitable for the nextstep without any further purification.

(iii) To a suspension of sodium hydride (0.8 g, 24 mmol, previouslywashed with hexanes (2×15 mL)) in anhydrous dimethylformamide (50 mL)was added a solution of 2-naphthenethanol in anhydrous dimethylformamide(50 mL). The resulting mixture was stirred at room temperature for 30min.

(iv)(1R,2R)/(1S,2S)-2-(1-Acetylpiperazinyl)-1-(2-naphthenethoxy)cyclohexanemonohydrochloride: the mesylate (ii) in solution in anhydrousdimethylformamide (50 mL) was added quickly to the alkoxide mixture(iii) and the resulting mixture was heated to 80° C. for 16 hours. Thecooled reaction mixture was poured into ice water (800 mL) and extractedwith ethyl acetate (3×200 mL). The combined organic extracts wereback-washed with brine (200 mL) and the solvent was evaporated in vacuo.The residual oil was taken up with water (80 mL) and the resultingaqueous solution was acidified to pH 2 with 6M HCl aqueous solution. Theacidic aqueous solution was extracted with diethyl ether (3×40 mL) inorder to extract the unreacted 2-naphthenethanol. The pH of the aqueouslayer was adjusted to pH10 with 50% NaOH aqueous solution and extractedwith diethyl ether (3×40 mL). The combined organic extracts were driedover sodium sulfate and the solvent was evaporated in vacuo to yield thecrude free aminoether. Purification by column chromatography of silicagel using a mixture of ethyl acetate-dichloromethane (1:1, v/v) aseluent provided the pure free base. Conversion to the hydrochloride saltwas accomplished with ethereal HCl followed by recrystallization in amixture of ethanol-diethyl ether provided the title compound, having theelemental analysis indicated in Table 1.

Example 17(1R,2R)/(1S,2S)-2-(3-Ketopyrrolidinyl)-1-(2,6-dichlorophenethoxy)cyclohexanemonohydrochloride Compound #17

Compound #17 was prepared in 10 steps according to the proceduredescribed in Example 16. Steps (i) to (v) were identical to those inExample 16.

(vi) To a chilled (0° C.) solution of(1R,2R)/(1S,2S)-2-(1,4-dioxa-7-azaspiro[4.4]non-7-yl)cyclohexanol (27.77g, 120 mmol) and triethylamine (22 mL, 156 mmol) in dichloromethane (240mL) was added methanesulfonyl chloride (12.32 mL, 156 mmol). Thereaction mixture was stirred at 0° C. for 45 min. and then at roomtemperature for 3 hours. The reaction mixture was washed with water(2×100 mL) and the combined washings were back-extracted withdichloromethane (120 mL). The combined organic extracts were dried oversodium sulfate and the solvent was evaporated in vacuo to yield thecrude mesylate which was further pumped under high vacuum for 4 hoursprior to use in step ix.

(vii) 2,6-Dichlorophenethyl alcohol: a suspension of lithium aluminumhydride (13.75 g, 365.75 mmol) in anhydrous diethyl ether (500 mL) wasadded via a powder addition funnel 2,6-dichlorophenylacetic acid (50 g,243.75 mmol). The resulting reaction mixture was refluxed for 16 hoursand then quenched by slow addition of a sodium sulfate saturated aqueoussolution (25 mL). The resulting slurry was stirred for 3 hours and thenfiltered, the insoluble was carefully washed with diethyl ether (2×100mL). The combined ether filtrates were dried over sodium sulfate and thesolvent was evaporated in vacuo to yield 38.6 g (85% yield) of the titlecompound.

(viii) To sodium hydride (144 mmol, 4.32 g, 80% oil dispersion) inanhydrous ethylene glycol dimethyl ether (80 mL) was added a solution of2,6-dichlorophenethyl alcohol (27.65 g, 144 mmol) in anhydrous ethyleneglycol dimethyl ether (80 mL). The resulting mixture was stirred at roomtemperature under argon atmosphere for 4 hours.

(ix)(1R,2R)/(1S,2S)-2-[1,4-Dioxa-7-azaspiro[4.4]non-7-yl]-1-(2,6-dichlorophenethoxy)cyclohexane:The mesylate (vi) in anhydrous ethylene glycol dimethyl ether (80 mL)was added quickly to the alkoxide mixture (viii) and the resultingmixture was readily refluxed for 66 hours. The cooled reaction mixturewas poured into water (200 mL) and the organic solvent was evaporated invacuo. The residual aqueous solution was diluted with more water to avolume of 700 mL, acidified to pH 0.5 with 6M HCl aqueous solution andextracted with diethyl ether (2×600 mL). The pH of the aqueous layer wasadjusted to pH 5.9 and then the aqueous solution was extracted withdiethyl ether (700 mL). The organic extract was dried over sodiumsulfate and the solvent was evaporated in vacuo to yield 34.0 g of thetitle compound (70% yield).

(x)(1R,2R)/(1S,2S)-2-(3-Ketopyrrolidinyl)-1-(2,6-dichlorophenethoxy)cyclohexanemonohydrochloride: A mixture of(1R,2R)/(1S,2S)-2-[1,4-dioxa-7-azaspiro[4.4]non-7-yl]-1-(2,6-dichlorophenethoxy)cyclohexane(15.85 g, 38.9 mmol, step ix) and 6M HCl aqueous solution (100 mL) in2-butanone (400 mL) was refluxed for 16 hours. The cooled reactionmixture was diluted with water (100 mL) and the organic solvent wasevaporated in vacuo. The organic layer was further diluted with water(400 mL), extracted with diethyl ether (500 mL) and with dichloromethane(2×600 mL). The combined dichloromethane extracts were dried over sodiumsulfate and the solvent was evaporated in vacuo. Azeotropic distillationwith toluene provided the title compound which was further dried underhigh vacuum for 15 min. The hydrochloride salt was crystallized bytriturating in diethyl ether, the crystals were collected andrecrystallized from a mixture of ethanol-diethyl ether to yield 11.85 gof pure product (77% yield), having the elemental analysis indicated inTable 1.

Example 18(1R,2R)/(1S,2S)-2-[1,4-Dioxa-7-azaspiro[4.4]non-7-yl]-1-(1-naphthenethoxy)cyclohexanemonohydrochloride Compound #18

(1R,2R)/(1S,2S)-2-[1,4-Dioxa-7-azaspiro[4.4]non-7-yl]-1-(1-naphthenethoxy)cyclohexane(1.2 g, 3.14 mmol, from Example 15, step (viii)) in diethyl ether (80mL) was treated with ethereal HCl. The solvent was evaporated in vacuoand the residue was taken up with diethyl ether, triturating gave asolid, which was collected and precipitated from a mixture ofdichloromethane-diethyl ether to yield 0.85 g of the title compound,having the elemental analysis indicated in Table 1.

Example 19(1R,2S)/(1S,2R)-2-(4-Morpholinyl)-1-[(2-trifluoromethyl)phenethoxy]cyclohexanemonohydrochloride Compound #19

(i) 2-(4-Morpholinyl)cyclohexanone: To a chilled (−70° C.) solution ofoxalyl chloride (20 mL, 0.23 mol) in dichloromethane (500 mL) was addeddropwise a solution of anhydrous dimethylsulfoxide (34 mL, 0.48 mol) indichloromethane (50 mL) and the resulting mixture was stirred for 5 min.at a temperature below −60° C. Then a solution of(1R,2R)/(1S,2S)-2-(4-morpholinyl)cyclohexanol (37.05 g, 0.2 mol) indichloromethane (50 mL) was added dropwise in order to maintain thereaction temperature below −60° C. and the reaction mixture was stirredfor 15 min. Triethylamine (140 mL) was added dropwise to the reactionmixture, keeping the reaction temperature below −50° C., and then thereaction mixture was allowed to warm up to room temperature. Thereaction mixture was poured into water (600 mL) and the aqueous layerwas separated and extracted with dichloromethane (2×500 mL). Thecombined organic layers were dried over sodium sulfate and the solventwas removed in vacuo. Vacuum distillation yielded 35.1 g (96% yield) ofthe title compound.

(ii) 2-(4-Morpholinyl)cyclohexanol: To a chilled (0° C.) suspension ofsodium borohydride (2.14 g, 56 mmol) in isopropanol (120 mL) was added asolution of 2-(4-morpholinyl)cyclohexanol (24.7 g, 135 mmol, step i) inisopropanol (80 mL). The resulting reaction mixture was stirred at 0° C.for 10 min. and then 30 min. at ambient temperature. Water (200 mL) wasadded to the reaction mixture and the organic solvent was evaporated invacuo. The residual aqueous solution was then extracted with ethylacetate (4×50 mL), the combined organic extracts were dried over sodiumsulfate and the solvent was evaporated in vacuo to yield 22.48 g of thetitle compound suitable for the next step without any furtherpurification.

(iii) (1S,2R)/(1R,2S)-2-(4-Morpholinyl)cyclohexyl2-(trifluoromethyl)phenylacetate: A mixture of2-(4-morpholinyl)cyclohexanol (7.41 g, 40 mmol, step ii),2-(trifluoromethyl)phenylacetic acid (10.21 g, 49 mmol) andp-toluenesulfonic acid monohydrate (40 mg) in toluene (60 mL) wasrefluxed in a Dean & Stark apparatus for 48 hours. To the cooledreaction mixture was added saturated sodium bicarbonate aqueous solution(40 mL), the aqueous layer was separated and extracted with ethylacetate (3×50 mL). The combined organic layers were dried over sodiumsulfate and the solvent was evaporated in vacuo to yield a mixture of(1S,2R)/(1R,2S)-2-(4-morpholinyl)cyclohexyl2-(trifluoromethyl)phenylacetate and(1R,2R)/(1S,2S)-2-(4-morpholinyl)cyclohexyl2-(trifluoromethyl)phenylacetate. Chromatography by dry column of thecis/trans mixture with mixtures of ethyl acetate-hexanes (+0.5%isopropylamine v/v) as eluents provided 3.19 g of the crude titlecompound contaminated by the starting material2-(4-morpholinyl)cyclohexanol. The crude product was partitioned betweendichloromethane (30 mL) and 0.5M HCl aqueous solution (7 mL). Theaqueous layer was separated and further extracted with dichloromethane(2×18 mL). The combined organic layers were dried over sodium sulfateand the solvent was evaporated in vacuo. Recrystallization from amixture of ethanol-hexanes yielded 2.78 g of the title compound.

(iv)(1S,2R)/(1R,2S)-2-(4-Morpholinyl)-1-[(2-trifluoromethyl)phenethoxy]cyclohexanemonohydrochloride: To a mixture of(1S,2R)/(1R,2S)-2-(4-morpholinyl)cyclohexyl2-(trifluoromethyl)phenylacetate (1.64 g, 4.28 mmol, step iii) andsodium borohydride (332 mg, 8.70 mmol) in anhydrous tetrahydrofuran (35mL) under reflux was added a solution of boron trifluoride diethyletherate (8.2 mL, 65 mmol) over 1.5 hour. The reaction mixture wasquenched by addition of water (˜70 mL), the organic solvent wasevaporated in vacuo and the pH of the residual aqueous solution wasadjusted to pH 9.6. The aqueous layer was extracted with diethyl ether(2×70 mL), the combined organic extracts were dried over sodium sulfateand the solvent was evaporated in vacuo. The residue was thenpartitioned between 0.5M HCl aqueous solution (50 mL) and diethyl ether(2×50 mL). The aqueous solution was basified to pH 5.9 and extractedwith diethyl ether (50 mL). The organic layer was collected, dried oversodium sulfate and the solvent was evaporated in vacuo to yield thecrude free aminoether. The free base was converted to the hydrochloridesalt by partition between 0.5M HCl aqueous solution (10 mL) anddichloromethane (10 mL). The acidic aqueous solution was extracted oncemore with dichloromethane (10 mL), the combined organic extracts weredried over sodium sulfate and the solvent was evaporated in vacuo.Recrystallization from a mixture of ethanol-hexanes yielded 636 mg (38%yield) of the title compound, having the elemental analysis indicated inTable 1.

Example 20(1R,2R)/(1S,2S)-2-(3-Ketopyrrolidinyl)-1-[3-(cyclohexyl)propoxy]cyclohexanemonohydrochloride Compound #20

(i) 3-Cyclohexyl-1-propyl bromide: To the chilled (0° C.)3-cyclohexyl-1-propanol (5 g, 35.15 mmol) was added slowly a solution ofphosphorus tribromide (1.1 mL, 17.6 mmol) in dichloromethane (2 mL).Upon completion of the addition, the reaction mixture was allowed towarm up to room temperature and was stirred for 4 hours. The reactionwas quenched by addition of saturated sodium bicarbonate aqueoussolution (5 mL) and 10% NaOH (10 mL). The resulting mixture wasextracted with diethyl ether (3×50 mL), the combined organic extractswere dried over sodium sulfate and the solvent was evaporated in vacuoto provide an oil. Vacuum distillation yielded 3.4 g (47% yield) of thetitle compound.

(ii)(1R,2R)/(1S,2S)-2-[1,4-Dioxa-7-azaspiro[4.4]non-7-yl]-1-[3-(cyclohexyl)propoxy]cyclohexane:To a suspension of sodium hydride (200 mg, 8.33 mmol) in anhydrousdimethylformamide (20 mL) was added a solution of(1R,2R)/(1S,2S)-2-(1,4-dioxa-7-azaspiro[4.4]non-7-yl)cyclohexanol (1.5g, 6.6 mmol) in anhydrous dimethylformamide (10 mL). The resultingmixture was stirred at room temperature for 30 min. and then a solutionof 3-(cyclohexyl)propyl bromide (1.67 g, 8.15 mmols) in anhydrousdimethylformamide was quickly added. The reaction mixture was stirred atroom temperature for 16 hours. The reaction mixture was poured intowater (200 mL) and then extracted with ethyl acetate (3×50 mL). Thecombined organic extracts were back-washed with brine (50 mL) and thesolvent was evaporated in vacuo. The residue was taken up with water (50mL) and the pH was adjusted to pH 1.0 with 6M HCl aqueous solution. Theacidic aqueous solution was extracted with diethyl ether (2×50 mL), thenbasified to pH 5.0-5.5 with 5M NaOH aqueous solution and extracted withdiethyl ether (3×50 mL). The combined organic extracts at pH 5.0-5.5were concentrated in vacuo to provide the crude title compound suitablefor the next step without any further purification.

(iii)(1R,2S)/(1S,2R)-2-(3-Ketopyrrolidinyl)-1-[3-(cyclohexyl)propoxy]cyclohexanemonohydrochloride:(1R,2R)/(1S,2S)-2-[1,4-Dioxa-7-azaspiro[4.4]non-7-yl]-1-[3-(cyclohexyl)propoxy]cyclohexane(ii) in a mixture of 6M HCl aqueous solution-butanone (1:4, v/v, 100 mL)was refluxed for 16 hours. The cooled reaction mixture was concentratedin vacuo and the residual aqueous solution was diluted with water (˜50mL). The acidic aqueous solution was extracted with diethyl ether (50mL) and then with dichloromethane (3×50 mL). The dichloromethaneextracts were dried over sodium sulfate and the solvent was evaporatedin vacuo to provide the crude title compound. The hydrochloride salt wascrystallized by triturating in a mixture of diethyl ether-hexanes (1:1,v/v, ˜200 mL) and then precipitated from a mixture ofdichloromethane-diethyl ether-hexanes to yield 0.8 g of the titlecompound, having the elemental analysis indicated in Table 1.

Example 21(1R,2R)/(1S,2S)-2-(3-Acetoxypyrrolidinyl)-1-(1-naphthenethoxy)cyclohexanemonohydrochloride Compound #21

(i)(1R,2R)/(1S,2S)-2-(3-Hydroxypyrrolidinyl)-1-(1-naphthenethoxy)cyclohexanemonohydrochloride: To a chilled (0° C.) solution of sodium borohydridein isopropanol (20 mL) was added a solution of(1R,2R)/(1S,2S)-2-(3-ketopyrrolidinyl)-1-(1-naphthenethoxy)cyclohexanemonohydrochloride (1.4 g, 3.75 mmol) in isopropanol (30 mL). Theresulting mixture was stirred at 0° C. for 15 min. and then 30 min. atroom temperature. The reaction was quenched by addition of water, thereaction mixture was evaporated to dryness and the residue was washedwith dichloromethane (2×20 mL). The dichloromethane washings were driedover sodium sulfate and the solvent was evaporated in vacuo to yield thetitle compound.

(ii)(1R,2R)/(1S,2S)-2-(3-Acetoxypyrrolidinyl)-1-(1-naphthenethoxy)cyclohexanemonohydrochloride: The intermediate alcohol (i) was then refluxed inacetic anhydride (15 mL) for 2 hours. The excess acetic anhydride wasremoved in vacuo; the residue was taken up with water (100 mL) andextracted with diethyl ether (2×30 mL). The aqueous solution wasbasified to pH 8.0 and extracted with diethyl ether (3×50 mL). Thecombined organic extracts were dried over sodium sulfate andconcentrated in vacuo. The residual oil was dissolved in a small amountof dichloromethane and a large volume of diethyl ether was added inorder to trigger crystallization of 1.0 g (65% yield) of the titlecompound, having the elemental analysis indicated in Table 1.

Example 22(1R,2R)/(1S,2S)-2-(4-Morpholinyl)-1-[(2,6-dichlorophenyl)methoxy]cyclohexanemonohydrochloride Compound #22

Compound #22 was prepared according to the Williamson ether synthesis.To a suspension of sodium hydride, 80% oil dispersion (337 mg, 11 mmol)in ethylene glycol dimethyl ether (20 mL) was added a solution of(1R,2R)/(1S,2S)-2-(4-morpholinyl)-1-cyclohexanol (2.0 g, 10.8 mmol) inethylene glycol dimethyl ether (10 mL). The resulting reaction mixturewas stirred at room temperature under argon atmosphere for 3 hours, thena solution of 2,6-dichlorobenzyl bromide in ethylene glycol dimethylether (10 mL) was added and the reaction mixture was refluxed for 16hours. The cooled reaction mixture was poured into water (40 mL) and theorganic solvent was evaporated in vacuo. The residual aqueous solutionwas diluted with more water (60 mL) and acidified to pH 0.5 with 6M HClaqueous solution. The acidic aqueous solution was extracted with diethylether (2×40 mL) and then the pH was adjusted to pH 5.5. Extraction withdiethyl ether (3×50 mL) followed by drying over sodium sulfate andconcentration in vacuo provided the pure aminoether. The hydrochloridesalt was precipitated by treatment of the free base with ethereal HCl.Recrystallization from a mixture of acetone-methanol-diethyl etheryielded 2.6 g (68% yield) of the title compound, having the elementalanalysis indicated in Table 1.

Example 23(1R,2R)/(1S,2S)-2-(3-Ketopyrrolidinyl)-1-[(2,6-dichlorophenyl)methoxy]cyclohexanemonohydrochloride Compound #23

Compound #23 was prepared in 7 steps according to the procedure detailedin Example 15. Steps (i) to (v) were identical to the ones described inExample 15. The ether synthesis (step vi) was carried out according tothe Williamson ether synthesis as in Example #22.

(vi)(1R,2R)/(1S,2S)-2-[1,4-Dioxa-7-azaspiro[4.4]non-7-yl]-1-[(2,6-dichlorophenyl)methoxy]cyclohexane:To a suspension of sodium hydride, 80% oil dispersion (222 mg, 7.25mmol) in ethyleneglycol dimethyl ether (20 mL) was added a solution of(1R,2R)/(1S,2S)-2-(1,4-dioxa-7-azaspiro[4.4]non-7-yl)cyclohexanol (1.5g, 6.60 mmol, step (v) of Example 15) in ethylene glycol dimethyl ether(10 mL). The resulting mixture was stirred at room temperature for 2hours and then a solution of 2,6-dichlorobenzyl bromide (1.9 g, 7.9mmol) in ethylene glycol dimethyl ether (10 mL) was added. The reactionmixture was refluxed for 16 hours under argon atmosphere, the solventwas evaporated in vacuo and the residue was taken up with water (70 mL).The aqueous solution was acidified to pH 0.5 with 6M HCl aqueoussolution and then extracted with diethyl ether (2×40 mL). Basificationof the aqueous solution to pH 4.5-5.5, followed by extraction withdiethyl ether (4×40 mL), drying of the combined organic extracts oversodium sulfate and evaporation of the solvent in vacuo provided theintermediate title compound.

(vii)(1R,2R)/(1S,2S)-2-(3-Ketopyrrolidinyl)-1-[(2,6-dichlorophenyl)methoxy]cyclohexanemonohydrochloride: The ketal intermediate (step vi) in a mixture of 6MHCl-butanone (1:4, v/v, 100 mL) was refluxed for 16 hours. The butanonewas evaporated in vacuo and the residual aqueous layer was diluted withmore water (100 mL). The acidic aqueous layer was extracted with diethylether (2×40 mL) and then with dichloromethane (3×40 mL). The combineddichloromethane extracts were dried over sodium sulfate and the solventwas evaporated in vacuo to provide the crude title compound. The productwas crystallized by triturating in diethyl ether and reprecipitated froma mixture of dichloromethane-diethyl ether to yield 1.8 g (72% yield) ofthe title compound, having the elemental analysis indicated in Table 1.

Example 24(1R,2R)/(1S,2S)-2-(3-Hydroxypyrrolidinyl)-1-(2,6-dichlorophenethoxy)cyclohexanemonohydrochloride Compound #24

To a solution of compound #17 (5.0 g, 12.7 mmol) in isopropanol (120 mL)was added sodium borohydride (2.0 g, 52.8 mmol) as a powder and theresulting mixture was stirred at room temperature until completion ofthe reaction. The reaction was quenched with water (40 mL) and thenconcentrated to dryness. The residue was washed with dichloromethane (50mL); the filtrate was dried over sodium sulfate, concentrated in vacuoto provide the title compound, which crystallized after 3 hours underhigh vacuum. Elemental analysis results of the product is shown in Table1.

Example 24A(1R,2R)/(1S,2S)-2-(3-Hydroxypyrrolidinyl)-1-(3,4-dimethoxyphenethoxy)cyclohexanemonohydrochloride Compound #24A

Compound #24A was prepared from(1R,2R)/(1S,2S)-2-(3-ketopyrrolidinyl)-1-(3,4-dimethoxyphenethoxy)cyclohexaneby reduction with sodium borohydride in a procedure similar to thatdescribed above for Compound #24. The substrate(1R,2R)/(1S,2S)-2-(3-ketopyrrolidinyl)-1-(3,4-dimethoxyphenethoxy)-cyclohexanewas synthesized according to the method described in Example 17.

Spectroscopic analyses of the product are consistent with the structurefor Compound #24A: ¹³C NMR (75 MHz, CDCl₃) δ 148.558, 147.255, 131.854,131.815, 120.663, 112.249, 111.004, 79.298, 79.112, 70.959, 70.735,69.620, 69.497, 63.276, 59.675, 59.351, 55.805, 55.712, 48.699, 48.443,36.346, 34.326, 34.169, 28.811, 28.765, 27.090, 27.032, 23.300, 23.222,22.921, 22.863. HR-MS: Calculated for C₂₀H₃₁N₄O 349.22531, found349.22578.

Example 25(1R,2R)/(1S,2S)-2-(3-Ketopyrrolidinyl)-1-(2,2-diphenylethoxy)cyclohexanemonohydrochloride Compound #25

Compound #25 was prepared in 10 steps according to a procedure identicalto the one described in Examples 15 and 17. Steps (i) to (v) wereidentical to Example 15.

(vi) To a chilled (0° C.) solution of(1R,2R)/(1S,2S)-2-(1,4-dioxa-7-azaspiro[4.4]non-7-yl)cyclohexanol (2.0g, 8.8 mmol) and triethylamine (2.1 mL, 15 mmol) in dichloromethane (30mL) was added methanesulfonyl chloride (0.9 mL, 11.44 mmol). Thereaction mixture was stirred at 0° C. for 45 min. and then at roomtemperature for 3 hours. The reaction mixture was diluted withdichloromethane (25 mL), washed with water (2×25 mL) and the combinedwashings were back-extracted with dichloromethane (25 mL). The combinedorganic extracts were dried over sodium sulfate and the solvent wasevaporated in vacuo to yield the crude mesylate which was further pumpedunder high vacuum for 30 min. prior to use in step ix.

(vii) (2,2-Diphenyl)ethyl alcohol: To lithium aluminum hydride (2.85 g,23.56 mmol) in anhydrous diethyl ether (150 mL) was added, as a powder,diphenylacetic acid (5.0 g, 56 mmol). The resulting reaction mixture wasgently refluxed for one hour. The reaction was quenched with sodiumsulfate saturated aqueous solution and the resulting precipitate wasfiltered off. The filtrate was concentrated in vacuo to yield 4.0 g (86%yield) of the title compound.

(viii) To sodium hydride, previously washed with hexanes, (253 mg, 10.56mmol) in suspension in ethylene glycol dimethyl ether (15 mL) was addeda solution of 2,2-diphenylethyl alcohol (2.09 g, 10.56 mmol, step vii)in ethylene glycol dimethyl ether (15 mL). The resulting mixture wasstirred at room temperature under argon atmosphere for 30 min.

(ix)(1R,2R)/(1S,2S)-2-(1,4-Dioxa-7-azaspiro[4.4]non-7-yl)-1-(2,2-diphenylethoxy)cyclohexane:The mesylate (vi) in ethylene glycol dimethyl ether (20 mL) was addedquickly to the alkoxide (viii) and the reaction mixture was refluxed for5 days. The cooled reaction mixture was concentrated in vacuo, theresidue was taken up with water (50 mL) and the pH was adjusted to pH1.0 with 6M HCl aqueous solution. The acidic aqueous solution wasextracted with diethyl ether (2×50 mL), the aqueous layer was collectedand basified to pH 6.0. Extraction with diethyl ether (2×50 mL) followedby drying over sodium sulfate and evaporation of the solvent in vacuoyielded 1.55 g (43% yield) of the title compound.

(x)(1R,2R)/(1S,2S)-2-(3-Ketopyrrolidinyl)-1-(2,2-diphenylethoxy)cyclohexanemonohydrochloride: A mixture of(1R,2R)/(1S,2S)-2-(1,4-dioxa-7-azaspiro[4.4]non-7-yl)-1-(2,2-diphenylethoxy)cyclohexane(1.55 g, 3.8 mmol) in 6M HCl-butanone (1:4, v/v, 50 mL) was refluxed for2 hours. The butanone was evaporated in vacuo and the residue was takenup with water (50 mL). The aqueous solution was extracted with diethylether (2×50 mL); the aqueous layer was collected and extracted withdichloromethane (2×50 mL). The combined dichloromethane extracts weredried over sodium sulfate and concentrated in vacuo to yield the crudetitle compound. The product was crystallized by triturating in diethylether and reprecipitated from a mixture of dichloromethane-diethyl etherto yield 1.21 g (80% yield) of the title compound, having the elementalanalysis indicated in Table 1.

Example 26(1R,2R)/(1S,2S)-2-(3-Thiazolidinyl)-1-(2,6-dichlorophenethoxy)cyclohexanemonohydrochloride Compound #26

(i) (1R,2R)/(1S,2S)-2-(3-Thiazolidinyl)cyclohexanol: To anhydrousmagnesium perchlorate (12.93 g, 53.3 mmol) was added a solution ofcyclohexene oxide (6.1 mL, 58.6 mmol) in anhydrous acetonitrile (25 mL)and the resulting mixture was stirred at room temperature for 20 min.Then a solution of thiazolidine (5.16 g, 55.0 mmol) in anhydrousacetonitrile was added and the reaction mixture was heated at 35° C. for16 hours. The reaction mixture was concentrated in vacuo and the residuewas partitioned between water (350 mL) and diethyl ether (350 mL). Theaqueous layer was separated and extracted once more with diethyl ether(350 mL). The combined organic extracts were dried over sodium sulfateand concentrated in vacuo to provide the crude product. The crudeaminoalcohol was purified by dry-column chromatography with a mixture ofethyl acetate-hexanes (1:1, v/v) as eluent to yield 4.83 g (47% yield)of the title compound.

(ii) To a chilled (0° C.) solution of(1R,2R)/(1S,2S)-2-(3-thiazolidinyl)cyclohexanol (3.17 g, 16.9 mmol) andtriethylamine (3.08 mL, 22.0 mmol) in dichloromethane (30 mL) was addeddropwise methanesulfonyl chloride (1.74 mL, 22.0 mmol). The reactionmixture was stirred at 0° C. for one hour and then at ambienttemperature for 3 hours. The reaction mixture was diluted withdichloromethane (20 mL) and washed with water (2×30 mL). The combinedwashings were back-extracted with dichloromethane (25 mL) and thecombined organic extracts were dried over sodium sulfate. Evaporation ofthe solvent in vacuo yielded the mesylate suitable for the next stepwithout any further purification.

(iii) To sodium hydride, 80% oil dispersion (608 mg, 20.28 mmol) inethylene glycol dimethyl ether (30 mL) was added a solution of2,6-dichlorophenethyl alcohol (3.87 g, 20.28 mmol, example 4, step vii)in ethyleneglycol dimethyl ether (15 mL). The resulting mixture wasstirred at room temperature under argon atmosphere for 2 hours.

(iv)(1R,2R)/(1S,2S)-2-(3-Thiazolidinyl)-1-(2,6-dichlorophenethoxy)cyclohexanemonohydrochloride: The mesylate (ii) in ethylene glycol dimethyl ether(15 mL) was added quickly to the alkoxide (iii) and the reaction mixturewas refluxed for 40 hours. The cooled reaction mixture was poured intowater (100 mL) and the organic solvent was evaporated in vacuo. Theresidual aqueous solution was diluted with more water (100 mL) and thepH was adjusted to pH 1.5. The acidic aqueous solution was extractedwith diethyl ether (3×100 mL), the combined organic extracts were driedover sodium sulfate and the solvent was removed in vacuo to provide thecrude free base. The product was purified by dry-column chromatographywith a mixture of ethyl acetate-hexanes (1:10, v/v) as eluent to yield2.4 g of the crude free aminoether. The pure product (1.0 g) wasconverted to the hydrochloride salt by treatment with ethereal HCl andthe resulting salt was recrystallized from a mixture of acetone-diethylether to yield 0.69 g of the title compound, having the elementalanalysis indicated in Table 1.

Example 27(1R,2S)/(1S,2R)-2-(3-Ketopyrrolidinyl)-1-(1-naphthenethoxy)cyclohexanemonohydrochloride Compound #27

Compound #27 was prepared in 8 steps according to the synthetic schemedepicted in FIG. 3. Steps (i) to (iv) were identical to those describedin Example 15.

(v) (1R,2R)/(1S,2S)-1-(1-Naphthenethoxy)-2-cyclohexanol: To anhydrousmagnesium perchlorate (270 mg, 1.2 mmol) in anhydrous acetonitrile (1.7mL) was added cyclohexene oxide (0.12 g, 1.2 mmol). The resultingmixture was stirred for 15 min. at room temperature and then1-naphthenethanol (2.7 g, 10.15 mmol) was added. The reaction mixturewas refluxed and more cyclohexene oxide (2.0 mL, 2.0 g, 20 mmol) wasadded to the refluxing reaction mixture at a rate of 0.4 mL/hour. Refluxwas stopped after 16 hours and the cooled reaction mixture waspartitioned between diethyl ether (50 mL) and saturated sodiumbicarbonate aqueous solution (30 mL). The aqueous layer was separatedand extracted twice more with diethyl ether (2×40 mL). The combinedorganic extracts were back-washed with water (15 mL), brine (15 mL) anddried over sodium sulfate. Evaporation of the solvent in vacuo yieldedthe crude title compound suitable for the next step without any furtherpurification.

(vi) 1-(1-Naphthenethoxy)-2-cyclohexanone: To a solution of(1R,2R)/(1S,2S)-2-(1-naphthenethoxy)-1-cyclohexanol (1.0 g, step v) indimethylformamide (20 mL) was added pyridinium dichromate (5.0 g, 13.2mmol) in small portions and the resulting reaction mixture was stirredat room temperature for 16 hours. The reaction mixture was poured intowater (100 mL) and the resulting slurry was extracted with diethyl ether(3×50 mL). The combined organic extracts were back-washed with 1M NaOHaqueous solution (30 mL), brine (30 mL) and dried over sodium sulfate.Evaporation of the solvent provided 1.0 g of the crude title compoundsuitable for the next step of the reaction.

(vii)(1R,2S)/(1S,2R)-2-(1,4-Dioxa-7-azaspiro[4.4]non-7-yl)-1-(1-naphthenethoxy)cyclohexane:To a solution of 1,4-dioxa-7-azaspiro[4.4]nonane (5.17 g, 40 mmol) and1-(1-naphthenethoxy)-2-cyclohexanone (1.79 g, 6.58 mmol, step vi, 77%pure) in anhydrous methanol (10 mL) was added 5N HCl methanolic solution(2.7 mL) and then sodium cyanoborohydride (397 mg, 6 mmol). The reactionmixture was further diluted with anhydrous methanol (7 mL) and stirredat room temperature for 16 hours. The reaction mixture was quenched byaddition of 6M HCl aqueous solution (40 mL), the organic solvent wasevaporated in vacuo, the residual aqueous solution was diluted to 100 mLwith water and the pH was adjusted to pH 0.5 with 6M HCl aqueoussolution. The acid aqueous layer was extracted with diethyl ether (100mL); the aqueous layer was separated and basified to pH 6.7 with 5M NaOHaqueous solution. Extraction with diethyl ether (100 mL), followed bydrying over sodium sulfate and evaporation of the solvent in vacuoprovided, after purification by dry-column chromatography with mixturesof ethyl acetate-hexanes (1:9 to 1:6, v/v, +0.5% v/v isopropylamine) aseluents, 1.28 g of crude(1R,2S)/(1S,2R)-2-(1,4-dioxa-7-azaspiro[4.4]non-7-yl)-1-(1-naphthenethoxy)cyclohexaneand(1R,2R)/(1S,2S)-2-(1,4-dioxa-7-azaspiro[4.4]non-7-yl)-1-(1-naphthenethoxy)cyclohexane.Separation of(1R,2S)/(1S,2R)-2-(1,4-dioxa-7-azaspiro[4.4]non-7-yl)-1-(1-naphthenethoxy)cyclohexanefrom(1R,2R)/(1S,2S)-2-(1,4-dioxa-7-azaspiro[4.4]non-7-yl)-1-(1-naphthenethoxy)cyclohexanewas performed by preparative HPLC (Waters Delta Prep 4000, PrePakcartridge 40×100 mm, isopropanol-hexanes (2:98, v/v, +0.05% v/vdiethylamine)) to yield 590 mg of the title compound.

viii)(1R,2S)/(1S,2R)-2-(3-Ketopyrrolidinyl)-1-(1-naphthenethoxy)cyclohexanemonohydrochloride: A mixture of(1R,2S)/(1S,2R)-2-(1,4-dioxa-7-azaspiro[4.4]non-7-yl)-1-(1-naphthenethoxy)cyclohexane(480 mg, 1.23 mmol, step vii) in 6M HCl aqueous solution-butanone (1:4,v/v, 40 mL) was refluxed for 2 hours. The organic solvent was evaporatedin vacuo, the residual aqueous solution was diluted to 50 mL with waterand extracted twice with diethyl ether (2×50 mL) and then thrice withdichloromethane (3×50 mL). The combined dichloromethane extracts weredried over sodium sulfate and the solvent was evaporated in vacuo, theresidual oil was further dried by azeotropic distillation of toluene.The title compound was crystallized by triturating in hexanes (430 mg,93% yield), and has elemental analysis indicated in Table 1.

TABLE 1 Compound Formula Calculated Found #1 C₂₂H₃₀NO₂Cl C 70.29, H8.04, N 3.73% C 69.36, H 8.17, N 3.73% #2 C₂₂H₃₀NO₂Cl C 70.29, H 8.04, N3.73% C 69.78, H 8.06, N 3.56% #3 C₁₈H₂₇NO₂BrCl C 53.41, H 6.72, N 3.46%C 53.16, H 6.77, N 3.35% #4 C₂₂H₃₀NO₃Cl C 67.42, H 7.72, N 3.57% C67.31, H 7.75, N 3.59% #5 C₁₈H₂₇NO₃BrCl C 51.38, H 6.47, N 3.33% C51.38, H 6.21, N 3.28% #6 C₂₀H₃₂NO₄Cl C 62.24, H 8.36, N 3.63% C 61.69,H 8.64, N 3.63% #7 C₂₂H₃₀NOCl C 73.41, H 8.40, N 3.89% C 73.26, H 8.64,N 3.94% #8 C₂₀H₂₈NO₂SCl C 62.89, H 7.39, N 3.67% C 61.94, H 7.42, N3.70% #9 C₂₀H₂₈NO₂SCl C 62.89, H 7.39, N 3.67% C 62.53, H 7.56, N 3.64%#10 C₁₈H₂₇NO₂BrCl C 53.41, H 6.72, N 3.46% C 53.29, H 6.94, N 3.57% #11C₁₈H₂₇NO₂BrCl C 53.41, H 6.72, N 3.46% C 52.61, H 7.46, N 4.01% #12C₂₁H₃₄NO₄Cl C 63.06, H 8.57, N 3.50% C 62.45, H 8.41, N 3.45% #14C₁₈H₂₆NO₂Cl₃ C 54.77, H 6.64, N 3.55% C 58.80, H 6.85, N 3.51% #15C₂₂H₂₈NO₂Cl C 70.67, H 7.55, N 3.75% C 70.12, H 7.55, N 3.73% #16C₂₄H₃₃N2O₂Cl•H₂O C 63.63, H 8.23, N 6.18% C 62.93, H 8.56, N 6.05% #17C₁₈H₂₄NO₂Cl₃ C 55.05, H 6.16, N 3.57% C 54.39, H 6.30, N 3.49% #18C₂₄H₃₂NO₃Cl C 68.97, H 7.72, N 3.35% C 68.49, H 7.64, N 3.31% #19C₁₉H₂₇NO₂ClF₃ C 57.94, H 6.91, N 3.56% C 57.75, H 6.91, N 3.56% #20C₁₉H₃₄NO₂Cl C 66.35, H 9.96, N 4.07% C 66.22, H 9.72, N 4.12% #21C₂₄H₃₂NO₃Cl C 68.97, H 7.72, N 3.35% C 67.52, H 7.99, N 3.17% #22C₁₇H₂₄NO₂Cl₂•H₂O C 51.21, H 6.57, N 3.51% C 51.03, H 6.57, N 3.36% #23C₁₇H₂₂NO₂Cl₂ C 53.91, H 5.86, N 3.70% C 53.88, H 5.79, N 3.59% #24C₁₈H₂₆NO₂Cl₃•H₂O C 52.38, H 6.84, N 3.39% C 53.98, H 7.24, N 3.33% #25C₂₄H₃₀NO₂Cl C 72.07, H 7.56, N 3.50% C 71.87, H 7.57, N 3.51% #26C₁₇H₂₄NOCl₃S C 51.46, H 6.10, N 3.53% C 51.48, H 5.86, N 3.44% #27C₂₂H₂₈NO₂Cl C 70.67, H 7.55, N 3.75% C 70.63, H 7.53, N 3.65%

Example 28 Assessment of Antiarrhythmic Efficacy

Antiarrhythmic efficacy was assessed by investigating the effect of acompound on the incidence of cardiac arrhythmias in conscious ratssubject to coronary artery occlusion. Rats weighing 200-300 gms weresubjected to preparative surgery and assigned to groups in a randomblock design. In each case, the animal was anesthetized with halothaneduring surgical preparation. The left femoral artery was cannulated formeasurement of mean arterial blood pressure and withdrawal of bloodsamples. The left femoral vein was also cannulated for injection ofdrugs. The thoracic cavity was opened and a polyethylene occluderloosely placed around the left anterior descending coronary artery. Thethoracic cavity was then closed. ECG was recorded by insertion ofelectrodes placed along the anatomical axis of the heart. All cannulaeand electrode leads were exteriorized in the mid scapular region. In arandom and double-blind manner, about 0.5 to 2 hours post-surgery, aninfusion of vehicle, or the compound to be tested was given. After 15minutes infusion, the occluder was pulled so as to produce coronaryartery occlusion. ECG, arrhythmias, blood pressure, heart rate andmortality were monitored for 30 minutes after occlusion. Arrhythmiaswere recorded as ventricular tachycardia (VT) and ventricularfibrillation (VF) and scored according to Curtis, M. J. and Walker, M.J. A., Cardiovasc. Res. 22:656 (1988) (see Table 2).

TABLE 2 Score Description 0 0-49 VPBs 1 50-499 VPBs 2 >499 VPBs and/or 1episode of spontaneously reverting VT or VF 3 >1 episode of VT or VF orboth (>60 s total combined duration) 4 VT or VF or both (60-119 s totalcombined duration) 5 VT or VF or both (>119 s total combined duration) 6fatal VF starting at >15 min after occlusion 7 fatal VF starting atbetween 4 min and 14 min 59 s after occlusion 8 fatal VF starting atbetween 1 min and 3 min 59 s after occlusion 9 fatal VF starting <1 minafter occlusion Where: VPB = ventricular premature beats VT =ventricular tachycardia VF = ventricular fibrillation

Rats were excluded from the study if they did not exhibit pre-occlusionserum potassium concentrations within the range of 2.9-3.9 mM. Occlusionis associated with increases in R-wave height and “S-T” segmentelevation; and an occluded zone (measured after death by cardiogreen dyeperfusion) in the range of 25%-50% of total left-ventricular weight.

Table 3 describes the result of tests of the compounds described thereinas values of a given infusion rate in micromol/kg/min. (ED₅₀AA) whichwill reduce the arrhythmia score in treated animals to 50% of that shownby animals treated only with the vehicle in which the test drug(s) isdissolved.

TABLE 3 Compound ED₅₀AA #1 0.8 #2 1.0 #3 2.1 #4 2.0 #5 3.0 #6 4.0 #7 4.0#8 1.0 #9 1.0 #10 2.0 #11 1.0 #14 1.5 #15 0.43 #17 1.1 #19 1.4 #21 1.4#22 1.8 #23 2.1 #24 0.6 #25 2.5 #26 6.5

Example 29 Measurement of ECG Parameters

Rats weighing 200-250 gms were used in this example. Animals wereanesthetized with 60 mg/kg pentobarbitone i.p. The carotid artery andjugular vein were cannulated for measurement of blood pressure and druginjection, respectively. ECG was recorded by insertion of electrodesplaced along the anatomical axis of the heart. All compounds were givenas bolus injections.

Various ECG parameters were measured. Table 4 describes the results ofthe tests as ED₂₅ (micromol/kg) which are the doses required to producea 25% increase in the parameter measured (ne=not estimated). Theincreases in P-R interval and QRS interval indicate cardiac sodiumchannel blockage while the increase in Q-T interval indicates ancillarycardiac potassium channel blockage which is the property of a type 1aantiarrhythmic.

TABLE 4 Compound PR QRS QT #1 NE NE 2.5 #2 5.6 8 2.0 #3 32 16 3.0 #6 NENE NE #7 1.1 1.5 0.9 #14 — 21.5 1.4 #15 15.8 7.8 3.4 #17 30 26 4.2 #211.7 2.3 1.6 #23 — 17.2 2.7 #24 1.4 1.6 1.0 #26 2.3 — 10

Example 30 Assessment of Sodium Channel Blockage

Rats were prepared according to the preceding procedure. Two silverstimulating electrodes were inserted through the chest wall andimplanted in the left ventricle. Square wave stimulation was used todetermine threshold current for capture, ventricular fibrillationthreshold current, and effective refractory period (Howard, P. G. andWalker, M. J. A., Proc. West. Pharmacol. Soc. 33:123-127 (1990)). Table5 contains ED₂₅ values for these indices of cardiac sodium channelblockage, where the ED₂₅ is the infusion rate in micromol/kg/minute ofcompound required to elicit a 25% increase from control. The increasesin refractoriness indicate ancillary blockage of potassium channels. Thethreshold current for capture is represented by “It”. The fibrillationthreshold current is represented by “VFT”. The effective refractingperiod is represented by “ERP”.

TABLE 5 Compound It VFT ERP #1 2.8 1.4 1.5 #2 0.9 0.7 1.3 #3 5.8 NE 4.0#7 0.7 0.2 0.4 #14 6.4 — 1.7 #15 5 1.2 1.6 #17 6 7.3 7.1 #23 7.6 6.2 5#24 1.7 1.2 1.1 #26 10.5 9 5.4

Example 31 Canine Vagal-AF Model General Methods

Mongrel dogs of either sex weighing 15-49 kg were anesthetized withmorphine (2 mg/kg im initially, followed by 0.5 mg/kg IV every 2 h) andα-chloralose (120 mg/kg IV followed by an infusion of 29.25 mg/kg/h;St.-Georges et al., 1997). Dogs were ventilated mechanically with roomair supplemented with oxygen via an endotracheal tube at 20 to 25breaths/minute with a tidal volume obtained from a nomogram. Arterialblood gases were measured and kept in the physiological range (SAO₂>90%,pH 7.30-7.45). Catheters were inserted into the femoral artery for bloodpressure recording and blood gas measurement, and into both femoralveins for drug administration and venous sampling. Catheters were keptpatent with heparinized 0.9% saline solution. Body temperature wasmaintained at 37-40° C. with a heating blanket.

The heart was exposed via a medial thoracotomy and a pericardial cradlewas created. Three bipolar stainless steel, Teflon™-coated electrodeswere inserted into the right atria for recording and stimulation, andone was inserted into the left atrial appendage for recording. Aprogrammable stimulator (Digital Cardiovascular Instruments, Berkeley,Calif.) was used to stimulate the right atrium with 2 ms, twicediastolic threshold pulses. Two stainless steel, Teflon™-coatedelectrodes were inserted into the left ventricle, one for recording andthe other for stimulation. A ventricular demand pacemaker (GBM 5880,Medtronics, Minneapolis, Minn.) was used to stimulate the ventricles at90 beats/minute when (particular during vagal-AF) the ventricular ratebecame excessively slow. A P23 ID transducer, electrophysiologicalamplifier (Bloom Associates, Flying Hills, Pa.) and paper recorder(Astromed MT-95000, Toronto, ON, Canada) were used to record ECG leadsII and III, atrial and ventricular electrograms, blood pressure andstimulation artefacts. The vagi were isolated in the neck,doubly-ligated and divided, and electrodes inserted in each nerve (seebelow). To block changes in β-adrenergic effects on the heart, nadololwas administered as an initial dose of 0.5 mg/kg iv, followed by 0.25mg/kg IV every two hours.

Atrial Fibrillation Model

Drug effects to terminate sustained AF maintained during continuousvagal nerve stimulation were assessed. Unipolar hook electrodes(stainless steel insulated with Teflon™, coated except for the distal1-2 cm) were inserted via a 21 gauge needle within and parallel to theshaft of each nerve. In most experiments, unipolar stimuli were appliedwith a stimulator (model DS-9F, Grass Instruments, Quincy, Mass.) set todeliver 0.1 ms square-wave pulses at 10 Hz and a voltage 60% of thatrequired to produce asystole. In some experiments, bipolar stimulationwas used. The voltage required to produce asystole ranged between 3-20volts. Under control conditions, a short burst of rapid atrial pacing(10 Hz, four times diastolic threshold) was delivered to induce AF whichwas ordinarily sustained for more than 20 minutes. The vagal stimulationvoltage was adjusted under control conditions, and then readjusted aftereach treatment to maintain the same bradycardic effect. AF was definedas rapid (>500 minute under control conditions), irregular atrial rhythmwith varying electrogram morphology.

Measurement of Electrophysiological Variables and Vagal Response

Diastolic threshold current was determined at a basic cycle length of300 ms by increasing the current 0.1 mA incrementally until stablecapture was obtained. For subsequent protocols current was set to twicediastolic threshold. Atrial and ventricular ERP was measured with theextrastimulus method, over a range of S1S2 intervals at a basic cyclelength of 300 ms. A premature extrastimulus S2 was introduced every 15basic stimuli. The S1S2 interval was increased in 5 ms increments untilcapture occurred, with the longest S1S2 interval consistently failing toproduce a propagated response defining ERP. Diastolic threshold and ERPwere determined in duplicate and averaged to give a single value. Thesevalues were generally within 5 ms. The interval between the stimulusartefact and the peak of the local electrogram was measured as an indexof conduction velocity. AF cycle length (AFCL) was measured duringvagal-AF by counting the number of cycles (number of beats−1) over a2-second interval at each of the atrial recording sites. The three AFCLsmeasurements were averaged to obtain an overall mean AFCL for eachexperimental condition.

The stimulus voltage-heart rate relationship for vagal nerve stimulationwas determined under control conditions in most experiments. The vagalnerves were stimulated as described above with various voltages todetermine the voltage which caused asystole (defined as a sinus pausegreater than 3 seconds). The response to vagal nerve stimulation wasconfirmed under each experimental condition and the voltage adjusted tomaintain the heart rate response to vagal nerve stimulation constant. Incases in which is was not possible to produce asystole, vagal nervestimulation was adjusted to a voltage which allowed two 20-minuteepisodes of vagal-AF to be maintained under control conditions (seebelow).

Experimental Protocols

The experimental groups studied are summarized in Table 5. Each dogreceived only one drug at doses indicated in Table 5. The first seriesof experiments were dose ranging studies, followed by blinded study inwhich 1-3 doses were given. All drugs were administered IV via aninfusion pump, with drug solutions prepared freshly in plasticcontainers on the day of the experiment. Vagal stimulation parameterswere defined under control conditions as described above, andmaintenance of AF during 20 minutes of vagal nerve stimulation undercontrol conditions was verified. After the termination of AF, thediastolic threshold and ERP of the atrium and ventricle were determined.Subsequently, these variables were reassessed in the atrium under vagalnerve stimulation. Electrophysiological testing usually took 15-20minutes. The heart rate response to vagal nerve stimulation wasconfirmed and the vagal-AF/electrophysiological testing protocol wasrepeated. A pre-drug blood sample was obtained and vagal-AFreinstituted. Five minutes later, one of the treatments was administeredat doses shown in Table 5. The total dose was infused over 5 minutes anda blood sample obtained immediately thereafter. No maintenance infusionwas given. If AF terminated within 15 minutes, the electrophysiologicalmeasurements obtained under control conditions were repeated and a bloodsample was obtained. If AF was not terminated by the first dose (within15 minutes), a blood sample was obtained and vagal stimulation wasdiscontinued to allow a return to sinus rhythm. The electrophysiologicalmeasurements were repeated and a third and final blood sample for thisdose was obtained. AF was reinitiated and the vagal-AF/druginfusion/electrophysiological testing protocol was repeated until AF wasterminated by the drug.

Statistical Analysis

Group data are expressed as the mean±SEM. Statistical analysis wascarried out for effective doses for AFCL, and ERP using a t-test with aBonferroini correction for multiple comparisons. Drug effects on bloodpressure, heart rate, diastolic threshold and ECG intervals wereassessed at the median dose for termination of AF. Two tailed tests wereused and a p<0.05 was taken to indicate statistical significance.

TABLE 6 EXPERIMENTAL GROUPS AND DOSES OF DRUGS Median dose Mean doserequired for Dose range Effective doses required for termination testedfor terminating termination of of AF Drug (μmol/kg) AF (μmol/kg) AF(μmol/kg) (μmol/kg) Flecainide 1.25-10 4-2.5; 1-10 4 ± 2 2.5

A single drug was administered to each dog over the dose range specifieduntil AF was terminated. The number of dogs in which AF was terminatedat each dose is shown (number of dogs-dose, in μmol/kg). The mean±SEM aswell as the median dose required to terminate AF is shown. Each dogreceived only one drug.

A number of the compounds of the present invention have been evaluatedby this method. The results showed that all of the compounds tested areeffective in terminating AF in the canine vagal-AF model. The conversionrates are similar to those reported for a variety of other class I andIII drugs in this model. The effectiveness of flecamide as a control inthe present study was comparable to that previously reported. All of thedrugs prolonged AFCL prior to termination of AF; effects which areglobally consistent with the wave length of re-entry model fortermination of AF. The tested compounds of the present invention did notreduce blood pressure or heart rate at the median dose for terminationof vagal-AF. The heart rate response to vagal nerve stimulation wassimilar in all groups and was not influenced by any of the compoundstested. Vagal nerve stimulation at 60% of the voltage required toproduce asystole (10±1 V) produced a 1.3±0.1 second pause.

Example 32 Canine Sterile Pericarditis Model

This model has been used to characterize the mechanisms of AF and atrialflutter (AFL). Waldo and colleagues have found that AF depends onreentry and that the site of termination is usually an area of slowedconduction. This canine model is prepared by dusting the exposed atriawith talcum powder followed by “burst” pacing the atria over a period ofdays after recovery. AF is inducible two days after surgery, however, bythe fourth day after surgical preparation; sustainable atrial flutter isthe predominant inducible rhythm. The inducibility of AF at day 2 issomewhat variable, such that only 50% of dogs may have sustained AF(generally <60 minutes) for a requisite of 30 minutes. However, thesustainable atrial flutter that evolves by the fourth day is induciblein most preparations. Atrial flutter is more readily “mapped” forpurposes of determining drug mechanisms. Inducibility of AF subsidesafter the fourth day post-surgery, similar to the AF that often developsfollowing cardiac surgery that the sterile pericarditis model mimics.There may be an inflammatory component involved in the etiology ofpost-surgery AF that would provide a degree of selectivity to anischaemia or acid selective drug. Similarly, while coronary arterybypass graft (CABG) surgery is performed to alleviate ventricularischaemia, such patients may also be at risk for mild atrial ischaemiadue to coronary artery disease (CAD). While atrial infarcts are rare,there has been an association between AV nodal artery stenosus and riskfor AF following CABG surgery. Surgical disruption of the autonomicinnervation of the atria may also play a role in AF following CABG.

Methods

Studies were carried out in a canine model of sterile percarditis todetermine the potency and efficacy of Compound 1 in terminating atrialfibrillation/flutter. Atrial flutter or fibrillation was induced 2 to 4days after creation of sterile pericarditis in adult mongrel dogsweighing 19 kg to 25 kg. In all instances, the atrial fibrillation orflutter lasted longer than 10 minutes. All studies were performed inaccordance with guidelines specified by our Institutional Animal Careand Use Committee, the American Heart Association Policy on ResearchAnimal Use, and the Public Health Service Policy on Use of LaboratoryAnimals.

Creation of the Sterile Pericarditis Atrial Fib/Flutter Model

The canine sterile pericarditis model was created as previouslydescribed. At the time of surgery, a pair of stainless steel wireelectrodes coated with FEP polymer except for the tip (O Flexon, Davisand Geck) were sutured on the right atrial appendage, Bachman's bundleand the posteroinferior left atrium close to the proximal portion of thecoronary sinus. The distance between each electrode of each pair wasapproximately 5 mm. These wire electrodes were brought out through thechest wall and exteriorized posteriorly in the interscapular region forsubsequent use. At the completion of surgery, the dogs were givenantibiotics and analgesics and then were allowed to recover.Postoperative care included administration of antibiotics andanalgesics.

In all dogs, beginning on postoperative day 2, induction of stableatrial fibrillation/flutter was attempted in the conscious, non-sedatedstate to confirm the inducibility and the stability of atrialfib/flutter and to test the efficacy of the drugs. Atrial pacing wasperformed through the electrodes sutured during the initial surgery. Onpostoperative day 4, when stable atrial flutter was induced, theopen-chest study was performed.

For the open-chest study, each dog was anesthetized with pentobarbital(30 mg/kg IV) and mechanically ventilated with 100% oxygen by use of aBoyle model 50 anesthesia machine (Harris-Lake, Inc.). The bodytemperature of each dog was kept within the normal physiological rangethroughout the study with a heating pad. With the dog anesthetized, butbefore the chest was opened, radiofrequency ablation of the His bundlewas performed to create complete atrioventricular (AV) block by standardelectrode catheter techniques. This was done to minimize thesuperimposition of atrial and ventricular complexes during subsequentrecordings of unipolar atrial electrograms after induction of atrialflutter. After complete AV block was created, an effective ventricularrate was maintained by pacing of the ventricles at a rate of 60 to 80beats per minute with a Medtronic 5375 Pulse Generator (Medtronic Inc.)to deliver stimuli via the electrodes sutured to the right ventricleduring the initial surgery.

Determination of Stimulus Thresholds and Refractory Periods DuringPacing

For the induction of AF/AFL, one of two previously described methods wasused: (1) introduction of one or two premature atrial beats after atrain of 8 paced atrial beats at a cycle length of 400 ms, 300 ms, 200ms, or 150 ms, or (2) rapid atrial Pacing for Periods of 1 to 10 secondsat rates incrementally faster by 10 to 50 beats per minute than thespontaneous sinus rate until atrial flutter was induced or there was aloss of 1:1 atrial capture. Atrial pacing was performed from either theright atrial appendage electrodes or the posteroinferior left atrialelectrodes. All pacing was performed using stimuli of twice thresholdfor each basic drive train with a modified Medtronic 5325 programmable,battery-powered stimulator with a pulse width of 1.8 ms.

After the induction of stable atrial fib/flutter (lasting longer than 10minutes), the atrial fib/flutter cycle length was measured and theinitial mapping and analysis were performed to determine the location ofthe atrial fib/flutter reentrant circuit. Atrial flutter was defined asa rapid atrial rhythm (rate, >240 beats per minute) characterized by aconstant beat-to-beat cycle length, polarity, morphology, and amplitudeof the recorded bipolar electrograms.

Drug Efficacy Testing Protocol

1. Effective refractory periods (ERPs) were measured from three sites:right atrial appendage (RAA), posterior left atrium (PLA), and Bachman'sBundle (BB), at two basic cycle lengths 200 and 400 ms.

2. Pace induce A-Fib or AFL. This was attempted for one hour. If noarrhythmia was induced, no further study was done on that day.

3. If induced, AF must have been sustained for 10 minutes. Then awaiting period was allowed for spontaneous termination or 20 minutes,whichever came first.

4. AF was then reinduced and 5 minutes was allowed before starting druginfusion.

5. Drug was then infused in a bolus over 5 minutes.

6. If AF terminated with the first dose then a blood sample was takenand ERP measurements were repeated.

7. Five minutes was allowed for the drug to terminate. If there was notermination then the second dose was given over 5 minutes.

8. After termination and ERPs were measured, a second attempt toreinduce AF was tried for a period of ten minutes.

9. If reinduced and sustained for 10 minutes, a blood sample was takenand the study repeated from #3 above.

10. If no reinduction, then the study was over.

A number of the compounds of the present invention have been evaluatedby this method. The results showed that all of the compounds tested areeffective in terminating episodes of atrial fibrillation/flutter in thismodel. There was no proarrhythmia or cardiovascular adverse eventsobserved during drug treatment.

Example 33 In Vitro Assessment of Inhibition Activity of Ion ChannelModulating Compounds on Different Cardiac Ion Currents

Cell Culture:

The relevant cloned cardiac ion channels (e.g. Kv1.4, Kv1.5, Kv4.2,Kv2.1 etc.) were studied by transient transfection into HEK cells usingthe mammalian expression vector pcDNA3. Transfections for each channeltype were carried out separately to allow individual study of the ionchannel of interest. Cells expressing channel protein were detected bycotransfecting cells with the vector pHook-1 (Invitrogen, San Diego,Calif., USA). This plasmid encoded the production of an antibody to thehapten phOX, which when expressed is displayed on the cell surface.Equal concentrations of individual channel and pHook DNA were incubatedwith 10× concentration of lipofectAce in Modified Eagle's Medium (MEM,Canadian Life Technologies) and incubated with parent HEK cells platedon 25 mm culture dishes. After 3-4 hours the solution was replaced witha standard culture medium plus 20% fetal bovine serum and 1%antimycotic. Transfected cells were maintained in at 37 C in an air/5%CO2 incubator in 25 mm Petri dishes plated on glass coverslips for 24-48hours to allow channel expression to occur. 20 min prior to experiments,cells were treated with beads coated with phOX. After 15 min, excessbeads were washed off with cell culture medium and cells which had beadsstuck to them were used for electrophysiological tests.

Solutions:

For whole-cell recording the control pipette filling solution contained(in mM): KCl, 130; EGTA, 5; MgCI2, 1; HEPES, 10; Na₂ATP, 4; GTP, 0.1;and was adjusted to pH 7.2 with KOH. The control bath solution contained(in mM): NaCl, 135; KCl, 5; sodium acetate, 2.8; MgCl2, 1; HEPES, 10;CaCl2, 1; and was adjusted to pH 7.4 with NaOH. A low pH bath solutioncontained the same constituents as control bath, but pH was adjusted to6.4 using NaOH. All chemicals were from Sigma Chemical Co. (St-Louis,Mo.). The test ion channel modulating compound was dissolved to 10 mMstock solutions in water and used at concentrations between 0.5 and 100uM. All compounds were protected from the light during all experiments.

Electrophysiological Procedures:

Coverslips containing cells were removed from the incubator beforeexperiments and placed in a superfusion chamber (volume 250 μl)containing the control bath solution at 22 C to 23 C. All recordingswere made via the variations of the patch-clamp technique, using anAxopatch 200A amplifier (Axon Instruments, CA). Patch electrodes werepulled from thin-walled borosilicate glass (World Precision Instruments;FL) on a horizontal micropipette puller, fire-polished, and filled withappropriate solutions. Electrodes had resistances of 1.0-2.5 μohm whenfilled with control filling solution. Analog capacity compensation wasused in all whole cell measurements. In some experiments, leaksubtraction was applied to data. Membrane potentials have not beencorrected for any junctional potentials that arose between the pipetteand bath solution. Data were filtered at 5 to 10 kHz before digitizationand stored on a microcomputer for later analysis using the pClamp6software (Axon Instruments, Foster City, Calif.). Due to the high levelof expression of channel cDNA's in HEK cells, there was no need forsignal averaging. The average cell capacitance was quite small, and theabsence of ionic current at negative membrane potentials allowedfaithful leak subtraction of data.

Data Analysis:

The concentration-response curves for changes in peak and steady-statecurrent produced by the test compound were computer-fitted to the Hillequation:

f=1−1/[1+(IC50[D])^(n)]  [1]

where f is the fractional current (f=Idrug/Icontrol) at drugconcentration [D]; IC50 is the concentration producing half-maximalinhibition and n is the Hill coefficient. The rapid component ofinactivation induced by the test compound was much faster than thatobserved in the absence of drug. Therefore, we used this drug inducedtime-constant (τ_(block)) as an approximation of the drug channelinteraction kinetics, according to the equation:

1/τ_(block) =k ₊₁ [D]+k ⁻¹  [2a]

and Kd=k ⁻¹ /k ₊₁  [2b]

in which τ_(block) is the current decay time constant caused by thedrug; [D] is the concentration of drug; k₊₁ and k⁻¹ are the apparentrate constants of binding and unbinding for the drug, respectively. Thevoltage dependence of block for the uncharged drug was determined asfollows: leak-corrected current in the presence of drug was normalizedto matching control at each voltage above −20 mV. Using data points inthe range of full channel opening (≧+20 mV), we have calculated thefractional block (f=Idrug/Icontrol) at each potential and fitted data tothe Woodhull equation:

f=[D]/([D]+Kd*.e ^(−qzFE/RT))  [3]

where f, R, z and T have their usual meanings, q represents thefractional electrical distance, i.e., the fraction of the transmembraneelectrical field sensed by a single charge at the receptor site. Kd*represents the binding affinity at the reference voltage (0 mV).Experimental values are given as means±S.E. or S.D. as stated.

A number of the compounds of the present invention have been evaluatedby this method. The results showed that the compounds of the presentinvention tested are effective in blocking the various cardiac ionchannels. There are different dose responses in the activity to blockthe various cardiac currents for the different compounds tested.

Example 34 Assessment of Proarrhythmia (Torsade De Pointes) Risk of IonChannel Modulating Compounds in Primates

These experiments were carried out in Bogor, Indonesia. Experimentalprotocols and procedures were approved by the ethics review committee atLembaga Penelitial Institut Pertainian Bogor, Indonesia.

Methods

General Surgical Preparation:

All studies were carried out in male Macaca fascicularis weighingbetween 4 and 5.5 kg. Animals were fasted over night and pre-medicatedwith ketamine (10 mg/kg im). Both saphenous veins were cannulated and asaline drip instituted to keep the lines patent. Halothane anaesthesia(1.5% in oxygen) was administered via a face mask. Lidocaine spray (10%spray) was used to facilitate intubation. After achieving a sufficientdepth of anaesthesia, animals were intubated with a 4 or 5 Frenchendotrachial tube. After intubation halothane was administered via theendotracheal tube and the concentration was reduced to 0.75-1%.Artificial respiration was not used and all animals continued to breathespontaneously throughout the experiment. Blood gas concentrations andblood pH were measured using a blood gas analyser (AVO OPTI I). Thefemoral artery was cannulated to record blood pressure.

Blood pressure and a modified lead II ECG were recorded using a MACLAB4S recording system paired with a Macintosh PowerBook (2400c/180). Asampling rate of 1 kHz was used for both signals and all data wasarchived to a Jazz disc for subsequent analysis.

Vagal Nerve Stimulation:

Either of the vagi was isolated by blunt dissection and a pair ofelectrodes inserted into the nerve trunk. The proximal end of the nervewas crushed using a vascular clamp and the nerve was stimulated usingsquare wave pulses at a frequency of 20 Hz with a 1 ms pulse widthdelivered from the MACLAB stimulator. The voltage (range 2-10V) wasadjusted to give the desired bradycardic response. The targetbradycardic response was a reduction in heart rate by half. In caseswhere a sufficient bradycardic response could not be obtained, 10 μg/kgneostigmine iv was administered. This dose of neostigmine was also givenafter administration of the test drug in cases where the test drug hadvagolytic actions.

Test Compounds:

The test compounds were transported to Bogor, Indonesia on dry ice. Anear maximum tolerated bolus dose of the test compound, infused (iv)over 1 minute, was used to assess the risk of torsade de pointes causedby each ion channel modulating compound. The actual doses variedslightly depending on the animals weight. Clofilium, 30 μmol/kg, wasused as a positive comparison (control) for these studies. Theexpectation was that a high dose of drug would result in a highincidence of arrhythmias. The test compounds were dissolved in salineimmediately before administration.

The necessity of vagal nerve stimulation for the model was assessed byadministering 2 mg/kg clofilium iv without stimulating the vagal nerve.Animals included in this experiment had previously received the sametest compound 2-5 days prior to the experiment.

Experimental Protocol:

Each animal received a single dose of a given drug iv. Before startingthe experiment two, 30 second episodes of vagal nerve stimulation wererecorded. A five minute rest period was allowed between episodes andbefore starting the experiment. The test solution was administered as aniv bolus at a rate of 5 ml/minute for 1 minute using an infusion pump(total volume 5 ml). ECG and blood pressure responses were monitoredcontinuously for 60 minutes and the occurrence of arrhythmias was noted.The vagal nerve was stimulated for 30 seconds at the following timesafter injection of the drug: 30 seconds, 2, 5, 10, 15, 20, 25, 30 and 60minutes.

Blood samples (1 ml total volume) were taken from each treated animal atthe following times after drug administration: 30 seconds, 5, 10, 20, 30and 60 minutes as well as 3, 6, 24 and 48 hours. Blood samples taken upto 60 minutes after drug administration were arterial while those takenafter this time were venous. Samples were centrifuged, the plasmadecanted and frozen. Samples were kept frozen before analysis of plasmaconcentration of the drug and potassium.

Statistics:

The effect of drugs on blood pressure, heart rate and ECG intervals aredescribed as the mean±SEM for a group size of “n.”

A number of the compounds of the present invention have been evaluatedby this method. No proarrhythmia or cardiovascular adverse events weredetected.

Example 35 Assessment of Pain Blockage

Guinea pigs were shaved (backs only) and 6 aliquots (50 μl) of compoundsolution (10 mg/ml) were injected just beneath the skin to form 6 blebswhich were outlined with a permanent marker. Pain responses wereassessed as above on each bleb at regular intervals up to 4 hours postinjection and the duration of pain blockage was recorded for threeanimals for each test solution.

TABLE 7 Duration of Compound Blockage (hours) 1 2.5 2 3 3 2.5 11  3Saline 0

Example 36 Ion Channel Modulating Compounds for the Treatment andPrevention of Postoperative Arrhythmias

Postoperative arrhythmias such as atrial fibrillation (AF) and atrialflutter (AFL) are common after cardiac surgery. This exampledemonstrates the efficacy and safety of ion channel modulating compoundsof the present invention in converting AF or AFL to sinus rhythm (SR)after coronary artery bypass surgery (CABG), valvular surgery, or both.One specific isomer of Compound 24A, namely(1R,2R)-2-[(3R)-Hydroxy-pyrrolidinyl]-1-(3,4-dimethoxyphenethoxy)cyclohexanemonohydrochloride (Compound 24A-1) was used in these studies. Thisisomer may be synthesized as the racemic mixture of Compound 24A andthen isolated by techniques described herein. Alternatively, this isomermay be synthesized directly as described in U.S. patent application Ser.Nos. 10/977,343, 11/201,776, and 11/690,361, each of which is herebyincorporated by reference in its entirety.

Methods:

A multicenter, double-blind, randomized (2:1 Compound 24A-1 vs.placebo), placebo-controlled trial was performed on patients aged ≧18years who had normal SR preceding surgery; had undergone CABG and/orvalvular surgery within 7 days; and had documented AF or AFL between 24hours and 7 days after CABG or valvular surgery. Patients Patients wererandomly assigned in a 1:2 ratio to receive a 10-min in fusion ofplacebo or 3 mg/ml Compound 24A-1. After 15 min, a second 10-mininfusion of placebo or 2 mg/ml Compound 24A-1 was given if AF or AFLpersisted. Postdose evaluations included 24 hour holter monitoring,12-lead ECG recordings and assessment of vital signs, adverse events andAF/AFL symptoms. The primary efficacy measure was conversion of AF/AFLto SR within 90 min of first exposure for at least 1 minute.

Results:

A total of 190 patients were randomized (63 placebo and 127 Compound24A-1) and 161 (54 placebo and 107 Compound 24A-1) received treatment.The main reason for not receiving treatment was spontaneous conversionto SR (7 placebo and 17 Compound 24A-1). The mean age was 68, and mostpatients were men (75%) and white (74%). Among the patients giventreatment, 67% had undergone CABG surgery, 24% had valvular surgery, and9% had both. At entry, 93% of patients had AF and 7% had AFL.

Conversion to SR within 90 minutes was observed in 45% of patientsreceiving Compound 24A-1 compared to 15% of patients receiving placebo(p=0.0002). The proportion of patients with AF that converted to SR was47% for patients receiving Compound 24A-1 and 14% for patients receivingplacebo (p=0.0001). Of the patients converting to SR with Compound24A-1, the median time to conversion was 12 minutes and 75% converted onthe first dose.

Compound 24A-1 was safe and well tolerated in postoperative patients. Inthe 24-hr period following stuffy drug administration, adverse eventswere reported in 32% and 38% of patients given placebo and Compound24A-1, respectively, of which two were serious (complete AV block andhypotension) in the Compound 24A-1 group. There were no deaths or casesof torsades de pointes.

These studies demonstrated that Compound 24A-1 was effective and welltolerated in the conversion of AF/AFL to SR following surgery andestablished that the ion channel modulating compounds of the presentinvention may be used for the treatment and prevention of postoperativearrhythmias.

All publications and patent applications mentioned in this specificationor the accompanying Application Data Sheet are herein incorporated byreference to the same extent as if each individual publication or patentapplication was specifically and individually incorporated by reference.

From the foregoing it will be appreciated that, although specificembodiments of the invention have been described herein for purposes ofillustration, various modifications may be made without deviating fromthe spirit and scope of the invention. Accordingly, the invention is notlimited except as by the appended claims.

1. A method of preventing postoperative arrhythmia in a warm-bloodedanimal in need thereof, comprising administering to said animal atherapeutically effective amount of a composition comprising a compoundhaving the following structure:

as an isolated enantiomeric or diastereomeric isomer or as a mixturethereof, or as a pharmaceutically acceptable salt thereof, incombination with a pharmaceutically acceptable carrier, excipient ordiluent.
 2. The method of claim 1 wherein administration is by a routeselected from the group consisting of oral, topical, parenteral,sublingual, rectal, vaginal, and intranasal.
 3. The method of claim 2wherein the parenteral administration is selected from the groupconsisting of subcutaneous injection, intravenous injection,intramuscular injection, epidural injection, intrasternal injection, andinfusion.
 4. The method of claim 2 wherein the oral administrationcomprises administering an oral dosage form selected from the groupconsisting of a powder, a granule, a compressed tablet, a pill, acapsule, a cachet, a chewing gum, a wafer, and a lozenge.
 5. The methodof claim 1 wherein the arrhythmia is atrial arrhythmia.
 6. The method ofclaim 5 wherein the atrial arrhythmia is atrial fibrillation.
 7. Themethod of claim 5 wherein the atrial arrhythmia is atrial flutter. 8.The method of claim 1 wherein the arrhythmia is ventricular arrhythmia.9. The method of claim 8 wherein the ventricular arrhythmia isventricular fibrillation.
 10. The method of claim 1 wherein thepostoperative arrhythmia occurs following cardiac surgery.
 11. Themethod of claim 10 wherein the cardiac surgery is coronary artery bypasssurgery.
 12. The method of claim 1 wherein the compound is a mixture ofenantiomeric or diastereomeric isomers.
 13. The method of claim 12wherein the compound has the following structure:

or pharmaceutically acceptable salt thereof.
 14. The method of claim 12wherein the compound has the following structure:

or pharmaceutically acceptable salt thereof.
 15. The method of claim 1wherein the compound is an isolated enantiomeric or diastereomericisomer.
 16. The method of claim 15 wherein the compound has thefollowing structure:

or pharmaceutically acceptable salt thereof.
 17. The method of claim 15wherein the compound has the following structure:

or pharmaceutically acceptable salt thereof.
 18. The method of claim 15wherein the compound has the following structure:

or pharmaceutically acceptable salt thereof.
 19. The method of claim 15wherein the compound has the following structure:

or pharmaceutically acceptable salt thereof.
 20. The method of claim 17wherein the pharmaceutically acceptable salt is a monohydrochloridesalt.
 21. (canceled)